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Tin oxide (SnO2) with high conductivity and excellent photostability has been considered as one of the most promising materials for efficient electron transport layer (ETL) in perovskite solar cells (PSCs). Among them, SnO2 nanoparticles (NPs) dispersions have been extensively utilized due to their facile film formation. However, the inherent defects and agglomeration issues of SnO2 NPs, as well as the limited tunability and instability of the post‐treatment process for surface/interface engineering strategy, still hinder its further applications. Herein, a ligand‐management strategy implemented during the in situ synthesis of NPs that can effectively achieve uniform modification of NPs is proposed. During the synthesis of SnO2 NPs, the grafting reaction between diethyl 2‐chloromalonate (DCMA) and the surface of SnO2 NPs is completed. Compared with the post‐treatment process, this intrinsic DCMA‐passivated SnO2 (DCMA‐SnO2) effectively reduces the trap state density at the interface between perovskite and ETL while enhancing surface chemical stability. Consequently, PSCs based on DCMA‐SnO2 achieve a champion PCE of 25.39% for small cells (active area of 0.0655 cm2) and 20.61% for solar modules (active area of 23.25 cm2), demonstrating excellent shelf‐life/light soaking stability (advanced level of ISOS stability protocols). This ligand‐management strategy exhibits significant application potential in preparing high‐efficiency large‐area PSCs. [ABSTRACT FROM AUTHOR]

Efficient photoelectrochemical (PEC) water splitting is a pivotal technique to achieve sustainable hydrogen production, driving the exploration for high‐performance photoelectrodes. Antimony selenide (Sb2Se3) semiconductor has received significant attention due to its cost‐effectiveness, eco‐friendly nature, and favorable photoelectric properties. However, traditional Sb2Se3‐based photocathodes typically employ cadmium sulfide (CdS) as an electron transport layer (ETL), which introduces toxicity and stability issues, hindering their commercial application potential. This study develops a versatile method to improve the PEC performance of Sb2Se3‐based photocathodes by incorporating Cd‐free (Zn,Sn)O ETL. Comprehensive investigations demonstrate remarkable improvement in surface and heterojunction interface properties, leading to charge carrier dynamics optimization with highly interesting carrier separation efficiency of 96.5% and transfer efficiency of 93.6%. As a result, the champion Mo/Sb2Se3/(Zn,Sn)O/TiO2/Pt photocathode delivers a notable photocurrent density (Jph) of 31.8 mA cm−2 (close to its theoretical value), and a half‐cell solar‐to‐hydrogen (HC‐STH) conversion efficiency of 4.32%. This advancement highlights a promising pathway toward large‐scale and environmentally friendly solar hydrogen production applications. [ABSTRACT FROM AUTHOR]

Charge transport layers are critical components in perovskite solar cells (PSCs) for achieving satisfied power conversion efficiencies (PCEs) and device stability. However, these layers often bring incompatible interfaces and complex fabrication, limiting the stability and scalability of PSC technology. Here an alternative strategy of salt‐based catalyzer (SBC) is proposed to regulate the heterogeneous nucleation of perovskite, which enables uniform and well‐controlled perovskite coverage directly onto the salt‐treated substrate without electron transport layers (ETLs). By carefully adjusting the cations, anions, and the thickness of SBC, high‐quality perovskite films along with superior buried interfaces suppress the carrier recombination losses and strengthen the interfacial stability, promoting the resultant device to achieve a record PCE of 23.04%, which represents the highest reported efficiency for ETL‐free PSCs. Meanwhile, the SBC technique can be well extended to large‐area, flexible, and module‐based devices. More encouragingly, the SBC‐based unencapsulated devices exhibit remarkable operational stability by retaining over 90% of initial efficiency for 1540 h under illumination and for 6312 h in an air environment. This work provides an advisable way to fabricate efficient and stable ETL‐free PSCs toward reliable and cost‐effective production. [ABSTRACT FROM AUTHOR]

The electron transport layer (ETL) material plays a crucial role in determining the device efficiency and stability of organic solar cells (OSCs). Tin oxide (SnO2) semiconductor is commonly used as ETL in organic solar cells and recently has attracted significant attention. In this paper SnO2 particles deposited by pulsed laser deposition (PLD) are used as ETL layer in inverted organic solar cells with structure (FTO/SnO2/PTB7-Th:O-IDTBR/ MoO3/Ag). The characterizations of cell using the Ossila Solar Cell I-V Test System have been investigated as well as the structural properties of SnO2 thin film using a Field emission scanning electron microscope (FESEM), The atomic force microscopy (AFM) and X-ray spectrum have been also investigated. It has been found that the Power conversion efficiency (PCE) of solar cell is 15.08 %. The stability was measured for 30 min with continuous illumination under the ambient air conditions, it was decreasing gradually over the illumination period to about half initial value of efficiency. The FESEM images and XRD spectrum show that the films were crystalline. The XRD spectrum shows the presence of several peaks belonging to SnO2 nanoparticles. The optical properties of SnO2 film indicate the increase in the transmittance and refractive index spectrum, while the absorbance spectrum decreases, the maximum absorbance was observed at 320 nm wavelength and the optical energy gap record about 3.1 eV and the grain size for SnO2 reported around 20–60 nm. [ABSTRACT FROM AUTHOR]

As an electron transport layer (ETL) widely used in organic solar cells (OSCs), ZnO has problems with energy level mismatch with the active layer and excessive defects on the ZnO surface, which can reduce the efficiency of OSCs. Here, ZnO/ZrSe2 composite is fabricated by modifying ZnO with 2D ZrSe2. The XPS and first‐principles calculation (FPC) show that ZnO obtains electrons from ZrSe2 and forms interfacial dipoles toward the active layer, which decreases the work function of ZnO, thus reducing the interface barrier and favoring the collection of electrons in OSCs. At the same time, after ZrSe2 modification, the oxygen vacancy density on the ZnO surface decreases, thus improving the conductivity of ZnO. More importantly, the femtosecond transient absorption (Fs‐TA) shows that ZrSe2 selectively traps holes from the active layer, which prevents the holes from entering the ZnO, thereby reducing the probability of electron recombination. Finally, ZnO/ZrSe2 composite is used as a novel ETL in OSCs with PBDB‐T: ITIC, PM6:Y6 and PM6: L8‐BO as active layers, and obtaining 12.09%, 16.34%, and 18.24% efficiency, respectively. This study provides a method for the interface modification of ZnO, and further investigates the role of 2D nanosheets in the interface modification. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) systems are regarded as clean and sustainable energy sources and exhibit minimal pollution during their lifetime. The production of hazardous contaminants contaminating water resources, emissions of air pollutants during the manufacturing process, and the impact of PV installations on land use are important environmental factors to consider. The present study aimed to synthesise the F-doped Titanium dioxide (TiO2) thin films on a glass substrate employing spin coating followed by the sol-gel process ETL application purpose. Fluorine-doped TiO2 thin films were prepared using the sol-gel spin coating technique. The X-ray diffraction (XRD) results confirmed that the most intense peak was observed at 25.37° corresponding to the crystallographic plane (101) for anatase TiO2. The average transparency of TiO2 was increased by adding the doping level of fluorine and increment in the optical bandgap. The thickness of the thin film was kept at about 300 nm. The resistance of nanocrystalline thin films of different F doped TiO2 was decreased from 1.322×1012 O, 9.728×1011 O, as the F doping concentration was increased from pristine to 7 at. %. Based on electrical measurements, it was observed that a suitable electron transport layer (ETL) of F-doped TiO2 can be synthesized for photovoltaic applications. The present study offers a synthesis and analysis of F-doped TiO2 that can be used to improve the sustainability of PV manufacturing processes, improve its economic value, and mitigate its negative impact on the environment. [ABSTRACT FROM AUTHOR]

The potential of cerium oxide (CeOx) as an electron transport layer (ETL) was explored in inverted bulk heterojunction organic solar cells (BHJ OSCs), using a mixture of P3HT and PC61BM as the photoactive layer, and compared with the benchmark zinc oxide (ZnO). CeOx layers on indium tin oxide or glass were obtained by spin-coating a solution prepared from Ce(OAc)3·yH2O followed by thermal annealing which was optimized. CeOx layers were characterized by different analytical techniques such as X-ray photoelectron spectroscopy showing that thermal annealing at 200 °C for 15 minutes led to the formation of CeOx, with a value of x reaching 1.70. These optimized thin layers of CeOx were successfully used as an ETL in P3HT-PC61BM inverted OSCs exhibiting power conversion efficiencies (PCEs) reaching 1.7% whereas ZnO-based devices showed a maximum PCE of 3.2%. Although annealing at 450 °C led to CeOx layers with a higher x value of 1.79, the PCEs of the devices became significantly lower due to the appearance of large crystalline clusters in the CeOx layer, as shown by AFM, likely producing short circuits. ZnO thin films doped with 3 mol% of CeOx were tested leading to a slight decrease of the photovoltaic efficiency. Importantly, the efficiency of the CeOx-based OSCs increased up to 2.1% after two weeks and remained higher than the initial value after one month, while OSCs based on ZnO doped with CeOx retained 85% of their initial PCE after five months of storage. These results open up interesting perspectives for the development of stable electronic devices. [ABSTRACT FROM AUTHOR]

Sol–gel processed zinc oxide (ZnO) is one of the most widely used electron transport layers (ETLs) in inverted organic solar cells (OSCs). The high annealing temperature (≈200 °C) required for sintering to ensure a high electron mobility however results in severe damage to flexible substrates. Thus, flexible organic solar cells based on sol–gel processed ZnO exhibit significantly lower efficiency than rigid devices. In this paper, an indium‐doping approach is developed to improve the optoelectronic properties of ZnO layers and reduce the required annealing temperature. Inverted OSCs based on In‐doped ZnO (IZO) exhibit a higher efficiency than those based on ZnO for a range of different active layer systems. For the PM6:L8‐BO system, the efficiency increases from 17.0% for the pristine ZnO‐based device to 17.8% for the IZO‐based device. The IZO‐based device with an active layer of PM6:L8‐BO:BTP‐eC9 exhibits an even higher efficiency of up to 18.1%. In addition, a 1.2‐micrometer‐thick inverted ultrathin flexible organic solar cell is fabricated based on the IZO ETL that achieves an efficiency of 17.0% with a power‐per‐weight ratio of 40.4 W g−1, which is one of the highest efficiency for ultrathin (less than 10 micrometers) flexible organic solar cells. [ABSTRACT FROM AUTHOR]

The materials for electron transport layers (ETLs) play a significant role in the performance of polymer solar cells (PSCs) but face challenges, such as low electron transport mobility and conductivity, low solution processibility, and extreme thickness sensitivity, which will undermine the photovoltaic performance and hinder compatibility of large‐scale fabrication technique. To address these challenges, a new n‐type perylene diimide‐based molecule (PDINB) with two special amine‐anchored long‐side chains is designed and synthesized feasibly. PDINB shows very high solubility in common organic solvents, such as dichloromethane (>75 mg ml−1) and methanol with acetic acid as an additive (>37 mg ml−1), which leads to excellent film formability when deposited on active layers. With PDINB as ETLs, the photovoltaic performance of the PSCs is boosted comprehensively, leading to power conversion efficiency (PCE) up to 18.81%. Thanks to the strong self‐doping effect and high conductivity of PDINB, it displays an appreciable thickness‐tolerant property as ETLs, where the devices remain consistently high PCE values with the thickness varying from 5 to 30 nm. Interestingly, PDINB can be used as a generic ETL in different types of PSCs including non‐fullerene PSCs and all‐polymer PSCs. Therefore, PDINB can be a potentially competitive candidate as an efficient ETL for PSCs. [ABSTRACT FROM AUTHOR]

This investigation initiated by modelling the crystal structure of perovskite to explore the impact of different temperatures. Researchers modified the perovskite crystal structure and observed its response to temperature variations. The study involved assessing the efficiency and fill factor of perovskite solar cells, incorporating photovoltaic structures without specifying the electron transport layer material. The primary goal of this initiative is to provide power to buildings using environmentally acceptable components in perovskite solar cells. The promising efficiency and cost-effectiveness of manufacturing make perovskite solar cells an intriguing option for generating clean and sustainable energy. [ABSTRACT FROM AUTHOR]

In this work, a flexible perovskite photodetector is demonstrated with a transferable TiO2 nanorod (NR) as an electron transport layer (ETL). The TiO2 NRs are grown by the hydrothermal method on Ni metal buffer layer/Si (100) substrates. During the growth process of TiO2 NRs in solution, the Ni sacrificial buffer layer is removed by hydrochloric acid in the initial stage. The resulting suspended seed layer can then sustain the growth of TiO2 NRs in both the top and bottom directions. The successfully grown TiO2 NRs are now transferred onto an ITO‐coated PET substrate as an ETL for the flexible Cs2AgBiBr6 perovskite photodetectors. The fabricated photodetector operates under a wavelength of 405 nm, and at an external bias voltage of −0.3 V, it exhibits an outstanding performance with an on/off ratio of 1.23 × 104, photoresponsivity (R) of 0.666 A W−1, and a detectivity (D*) of 9.29 × 1012 Jones. In terms of flexibility, the optoelectronic performance of each device is well kept within 5% after 300 bending test cycles with a radius of 1 cm. The suggested transferable TiO2 NRs can improve the efficiency of flexible optoelectronic devices that require synergistic electron transfer effects by using heterostructures with TiO2 nanostructures. [ABSTRACT FROM AUTHOR]

In recent years, organic–inorganic hybrid perovskite (PVK) devices have attracted widespread attention with their high absorption coefficient and low-cost fabrication process. Formamidinium lead iodide (FAPbI3) perovskite solar cells (PSCs) have been reported to obtain high power conversion efficiencies (PCEs) due to the narrow bandgap. Zinc oxide (ZnO) has better electrical conductivity and high transmittance than tin (IV) dioxide (SnO2). However, the deprotonation behavior of ZnO limits its use in formamidinium (FA) or methylammonium (MA) devices, so it is mostly used in all-inorganic PSCs. In this work, to avoid the deprotonation behavior of ZnO, we prepared FAPbI3 PSCs using ZnO/SnO2 as bilayer electron transporting layers (ETLs), which improved the conductivity of the ETLs and promoted electron extraction and transfer. In addition, the decrease in the oxygen vacancy (Ov) on the bilayer ETLs contributed to the suppression of the non-radiative recombination of the device, thus enabling the achievement of a higher fill factor. As a result, the modified ETLs increased the PCE of FAPbI3 PSCs from 20.24% to 21.42% and improved the stability of the devices. The PCE of unpackaged devices increased steadily to 21.91% when stored in an N2 atmosphere for 183 days. [ABSTRACT FROM AUTHOR]

The fabrication of high‐performance perovskite solar cells on high‐haze fluorine‐doped tin oxide (FTO) substrates with superior light‐trapping capabilities necessitates a highly conformal electron transport layer at the bottom interface. Herein, a conformal low‐temperature processable all‐SnO2‐based electron transport layer (ETL) is successfully developed on high‐haze FTO by well‐anchoring a polyacrylic acid‐stabilized quantum dot‐SnO2 layer onto an atomic layer deposited SnO2 layer with a dense hydroxyl surface. The obtained ETL demonstrates excellent capabilities in simultaneously homogenizing the surface contact potential distribution, blocking hole transport, and suppressing non‐radiative recombination. Consequently, a champion device is achieved that delivers a remarkable power conversion efficiency (PCE) of up to 24.97%, with VOC × FF reaching 87.09% of the Shockley‐Queisser limit at a bandgap of 1.54 eV, which is the highest value among the ALD SnO2‐based PSCs. The homogeneous ETL further enabled the fabrication of a 1 cm2 PSC with a PCE of 23.18% and only a 10 mV loss in VOC compared to smaller‐area PSCs, showcasing its potential for large‐scale commercial applications. [ABSTRACT FROM AUTHOR]

Achieving both high efficiency and stability in organic solar cells (OSCs) remains a significant challenge. Inverted structure OSCs, compared to those with a normal structure, show great potential for combining high efficiency with enhanced stability. However, despite their improved stability, the efficiencies of inverted OSCs still lag behind those of conventional structure OSCs, largely due to the performance of electron transport layers (ETLs). Herein, a water‐soluble hybrid ETL is developed by modifying SnO2 nanoparticles with an aqueous potassium carboxylate salt, PMA. This modification effectively passivates the oxygen vacancy defects in the SnO2 nanoparticles and eliminates the light soaking issue observed in the control device. As a result, the PM6:Y6‐based device shows an improvement in efficiency from 16.68% to 17.85% with PMA modification. Notably, an exceptional efficiency of 19.07% is achieved for the PM6:BTP‐eC9‐based device using this hybrid ETL, marking the highest efficiency reported to date for single‐junction inverted OSCs. In addition, all tested OSCs with the hybrid ETL demonstrate superior stability under both thermal and light illumination at the maximum power point compared to the control devices. Furthermore, utilizing this water‐processed hybrid ETL, a large‐area module based on PM6:BO‐4Cl is fabricated and shows an outstanding efficiency of 15.02%. [ABSTRACT FROM AUTHOR]

Transparent conductive oxide (TCO)‐coated glasses are the most expensive and environmentally impacting components of perovskite solar cells (PSCs), comprising 56% of the total cost of a perovskite module and 96% of its carbon footprint. Thus, recycling TCO glasses from end‐of‐life perovskite modules can reduce both their levelized cost of electricity and energy payback time. In this work, tin oxide (SnO2)‐coated indium tin oxide glasses are refurbished from n‐i‐p PSCs employing dimethyl sulfoxide as a green solvent to dissolve the upper layers of the devices. Employing the recovered substrates, new‐generation PSCs are produced, which retain the same champion power conversion efficiency (PCE) of 22.6% as fresh samples and display an even higher average PCE. This performance enhancement is investigated through compositional and electrical analyses that demonstrate that the proposed recycling protocol induces beneficial surface modifications on the SnO2/perovskite interface and trap passivation, boosting charge extraction. [ABSTRACT FROM AUTHOR]

Not only can perovskite solar cells be exposed to high temperatures, up to 80 °C, depending on the operating environment, but absorbed energy is lost as heat, so it is important to have thermal stability for commercialization. However, in the case of the recently reported p-i-n structure solar cell, most of the electron and hole transport layers are composed of organic materials vulnerable to heat transfer, so the light absorption layer may be continuously exposed to high temperatures when the solar cell is operated. In this study, we attempted to improve the thermal conductivity of the electron transport layer using phenyl-C61-butyric acid methyl ester (PCBM) containing zinc oxide (ZnO). As a result, the thermal conductivity was improved by more than 7.4% and 23.5% by adding 6.57vol% and 22.38vol% of ZnO to PCBM, respectively. In addition, the insertion of ZnO resulted in changes in the electron transport behavior and energy level of the electron transport layer. As a result, it was confirmed that not only could the temperature stability of the perovskite thin film be improved, but the efficiency of the solar cell could also be improved from 14.12% to 17.97%. [ABSTRACT FROM AUTHOR]

Highlights: Developing a universal strategy of the p–n homojunction engineering that could significantly boost electron mobility of electron transport layer (ETL) by two orders of magnitude. Proposing a new mechanism based on p–n homojunction to explain inhibited carrier loss at buried interface. Setting a new performance benchmark as high as 25.50% for planar perovskite solar cells employing TiO2 as ETLs. Low-temperature processed electron transport layer (ETL) of TiO2 that is widely used in planar perovskite solar cells (PSCs) has inherent low carrier mobility, resulting in insufficient photogenerated electron transport and thus recombination loss at buried interface. Herein, we demonstrate an effective strategy of laser embedding of p-n homojunctions in the TiO2 ETL to accelerate electron transport in PSCs, through localized build-in electric fields that enables boosted electron mobility by two orders of magnitude. Such embedding is found significantly helpful for not only the enhanced crystallization quality of TiO2 ETL, but the fabrication of perovskite films with larger-grain and the less-trap-states. The embedded p–n homojunction enables also the modulation of interfacial energy level between perovskite layers and ETLs, favoring for the reduced voltage deficit of PSCs. Benefiting from these merits, the formamidinium lead iodide (FAPbI3) PSCs employing such ETLs deliver a champion efficiency of 25.50%, along with much-improved device stability under harsh conditions, i.e., maintain over 95% of their initial efficiency after operation at maximum power point under continuous heat and illumination for 500 h, as well as mixed-cation PSCs with a champion efficiency of 22.02% and over 3000 h of ambient storage under humidity stability of 40%. Present study offers new possibilities of regulating charge transport layers via p-n homojunction embedding for high performance optoelectronics. [ABSTRACT FROM AUTHOR]

The study of charge transfer in thin film solar cells made of several layers is of high importance since they may lose their energy via the recombination process at the interfaces, specifically at the interface of the electron transport layer (ETL) and perovskite. Titanium dioxide (TiO2) is mostly used as an ETL in perovskite solar cells due to its many advantages. However, TiO2 has some disadvantages, such as low electron mobility compared to the perovskite layer and electron trap states on its top at the interface. These effects cause the accumulation of carriers at the ETL/perovskite interface then the non-radiative recombination will be enhanced, which is considered as one of the significant losses in the Perovskite Solar Cells (PSCs). In this work, a new technique is taken for more optimal ETL doping. We fabricated the ETL layers with graded doping of platinum quantum dots (Pt QDs), in which Pt QDs concentration is high at the ETL/Perovskite interface and zero at the FTO/ETL interface. This strategy not only suppresses the recombination at the ETL/perovskite interface and subsequently enhances the device efficiency from 12.92 to 14.36% but also improves the stability of the PSCs. [ABSTRACT FROM AUTHOR]

Herein, a new heterojunction photovoltaic (PV) device is designed by incorporating molybdenum trioxide (MoO3) as a hole transport layer (HTL), tin sulfide (SnS) as an absorber, and tungsten disulfide (WS2) as an electron transport layer (ETL). The PV outputs of the proposed thin‐film solar cell (TFSC) of Ni/MoO3/SnS/WS2/FTO/Al are investigated using the widely used solar cell simulator (SCAPS‐1D). It is found that the SnS TFSC with suitable band alignments at both the SnS/WS2 and MoO3/SnS interfaces gives better photoconversion efficiency than the conventional one. To optimize the material properties, the performance parameters, including open‐circuit voltage (Voc), short‐circuit current density (Jsc), fill factor (FF), and efficiency, have been calculated by varying the influences of the material's thickness, doping concentration, bulk and interface defect densities, operational temperature, and work function of back‐contact. At optimized thicknesses of 0.1 μm for MoO3 HTL and 1.0 μm for SnS absorber, the efficiency is estimated to be 30.42% with Voc of 1.02 V, Jsc of 34.38 mA cm−2, and FF of 87.04% for the suggested TFSC. These outcomes imply that the nontoxic MoO3 and WS2 materials can be applied as HTL and ETL into the inexpensive, highly efficient, and environmentally friendly SnS‐based PV cell. [ABSTRACT FROM AUTHOR]

Tin dioxide (SnO2), one of the best electron transport layer materials for perovskite solar cells (PSCs), has high electrical conductivity and low photocatalytic activity. However, the defects in its inside and surface result in nonradiative recombination at the SnO2/perovskite interface. Complex and time‐consuming passivation methods are not conducive to the commercialization of PSCs, and simple passivation strategies should be used to improve the photovoltaic performance of the devices. Herein, a facile and efficient method is proposed to simultaneously passivate the inside and surface defects by adding histidine (HIS) to SnO2 colloidal solution. This one‐step doping strategy also modulates carrier dynamics at the SnO2/perovskite interface. HIS reduces suspended hydroxyl groups, oxygen vacancies, and uncoordinated Sn4+ defects on the surface of SnO2, as well as uncoordinated Pb2+ and halogen vacancy defects at the buried interface of perovskite. Surprisingly, HIS can prevent perovskite from decomposition to form PbI2, which further decomposes to photoactive metallic Pb0 and I, causing ion migration in PSC. As a result, the PSC efficiency has significantly improved 23.11% after HIS doping. The efficiency of unencapsulated device with HIS is 94% of the primary efficiency after storage in relative humidity = 70 ± 5% for 1000 h. [ABSTRACT FROM AUTHOR]

Context: Density functional theory (DFT) calculations are carried out on pure and doped rutile TiO 2 . The bandgap (E g ) for pristine, S-doped, Fe-doped, and Fe/S co-doped materials is direct, with values of 2.98 eV, 2.18 eV, 1.58 eV, and 1.40 eV. The effective mass of charge carriers (m*) and ratio of effective masses of holes to effective masses of electrons (R) are also investigated, and it is discovered that Fe/S co-doped materials have the lowest charge carrier recombination rate. The Fe/S co-doped material has the highest ε (ω) . α (ω) of doped materials shifted into the visible range. Due to the high dopant concentration in Fe and Fe/S-doped cases, the E g is lowered to a relatively small value; hence, only pristine and S-doped materials are verified as electron transport layer (ETL). A solar cell device analysis employing pure and S-doped rutile TiO 2 as ETL is completed using DFT-derived parameters in SCAPS-1D modeling software for the first time. For the optimized solar cells, current–voltage (IV) characteristics, quantum efficiency (QE), capacitance-voltage (CV) characteristics, and capacitance-frequency (Cf) characteristics are provided. The aim of the present study is to improve efficiency of perovskite solar cell by doping as well as to improve accuracy of simulation by applying DFT extracted parameters as input. From the analysis, improvement is found in efficiency of doped TiO 2 compared to un-doped TiO 2 . The efficiency of the PSC with S-doped ETL is 1.418% higher than the PSC with un-doped ETL. Method: Quantumwise Automistic Tool Kit (ATK) is used to extract DFT parameters. Using these DFT parameters as input in SCAPS-1D (Solar Cell Capacitance Simulator), solar cells for doped and un-doped material are simulated. The density functional theory (DFT)-based orthogonalized linear combination of atomic orbital (OLCAO) technique is used. Structural optimization is done using the LBFGS (Limited-memory Broyden-Fletcher-Goldfarb-Shanno). PBESol-GGA (Perdew-Burke-Ernzerhof solid-generalized gradient approximation) is applied as exchange correlation for calculating structural parameters, while MGGA-TB09 (meta-generalized gradient approximation-Tran and Blaha) is applied as exchange correlation for calculating optical and electronic properties. [ABSTRACT FROM AUTHOR]

Substandard printing quality of electron transport layers (ETLs) always leads to non‐ideal nucleation crystallization and bottom interface contact of the perovskite, followed by the formation of poor‐quality perovskite films with severe heterogeneity, which is the major source of non‐radiative recombination loss and environmental sensitivity of perovskite solar cells (PVSCs). These often result in serious photovoltaic performance loss, significant instability, and negative fabrication reproducibility. Herein, sodium phytate is proposed as a chelating agent for passivating the tin oxide (SnO2) ETLs to enable the stabilization of SnO2 nanoparticles and facilitate the printing of pinhole‐free films, thereby realizing the controlled nucleation crystallization in perovskite precursor. Thus, the printed PVSCs exhibit a champion power conversion efficiency up to 23.77% with negligible hysteresis effect. The unencapsulated devices demonstrate outstanding long‐term stability, which maintains over 80% of their initial efficiency under exposure to atmospheric environment (50% relative humidity) for 1500 hours, and a consistent and centralized distribution of efficiencies across all seasons, indicating their good reproducibility in diverse climatic atmospheres. [ABSTRACT FROM AUTHOR]

The SILAR method of thin film deposition has attracted the scientific community over the years due to its easiness, low cost, availability of room temperature deposition, and more over due to the variation in properties of thin films available by varying deposition parameters. This work is carried out in a way to comprehensively compare two ZnO thin film samples prepared from precursor media with Zinc Acetate (S1) and Zinc Chloride(S2) salts deposited by SILAR method in Perovskite Solar cell applications. The XRD, FTIR, Raman, FESEM, and UV-Visible analysis were carried out for identifying the structural, morphological, and optical quality of these samples. The role of these samples as Electron Transport Layer (ETL) in Perovskite Solar cell were identified using General purpose PhotoVoltaic Device model (GPVDM) simulation software which is well adapted for studying Solar cell architecture. It provided the output Solar cell parameters like Jsc, Voc, FF, PCE, etc and by varying the active layer and Hole Transport Layer (HTL) thicknesses, the optimized efficiency of devices with samples S1 and S2 were obtained as 21.88% and 21.96%.The results showed that SILAR-synthesized ZnO thin films could be potential candidates for ETL applications in Perovskite Solar cells. [ABSTRACT FROM AUTHOR]

There are many ways to boost the optical absorption efficiency of photovoltaic devices. It has been observed that the plasmonic effect is an efficient technique to increase the incident light collection and improve carrier dynamic control. Here, we made some modifications in the electron transport layer (ETL) and hole transport layer (HTL) of perovskite solar cells (PSCs). The hollow spheres of TiO2 nanoparticles (NP) of different sizes were incorporated in the ETL, and carbon nanoparticles were added to the HTL of the PSCs. Finite element method (FEM) was used to determine the UV–Vis absorption and bandgap energy results under AM 1.5 solar spectrum. General-purpose photovoltaic device model (GPVDM) and COMSOL Multiphysics version 5.3 are the software tools used in the analysis. Here, we introduced gold nanoparticles along with dielectric material (TiO2) of different geometries in the absorber layer of PSCs to investigate the optical absorption and bandgap energy of the PSC structure. For the monolayer structure, we have achieved a power conversion efficiency (PCE) of 24.23%, which is 2.54% higher than the bilayer structure of a Perovskite solar cell. In the absorber layer, we have also used a core@shell structure with metal as core and dielectric nanoparticles TiO2 and SiO2 as shell materials. The optical absorption in both Au@TiO2/Au@SiO2 core–shell and without plasmonic NP TiO2/SiO2 is 10.82% and 4.11%, respectively. These findings suggested that by using the plasmonic NPs the charge separation has been enhanced. Additionally, this study offers a very sophisticated method for enhancing the performance of overall photovoltaic devices. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) have attracted increasing research interest, but their performance depends on both the choice of materials and the process used. The materials can typically be treated in solution, which makes them well suited for roll-to-roll processing methods, but their deposition under ambient conditions requires overcoming some challenges to improve stability and efficiency. In this review, we highlight the latest advancements in photonic curing (PC) for perovskite materials, as well as for hole transport layer (HTL) and electron transport layer (ETL) materials. We present how PC parameters can be used to control the optical, electrical, morphological, and structural properties of perovskite HTL and ETL layers. Emphasizing the significance of these advancements for perovskite solar cells could further highlight the importance of this research and underline its essential role in creating more efficient and sustainable solar technology. [ABSTRACT FROM AUTHOR]

A small molecular phenanthroline derivative Phen‐NaDPO (3‐[6‐(diphenylphosphinyl)‐2‐naphthalenyl]‐1,10‐Phenanthroline) to modify tin oxide (SnO2) electron‐transport layer (ETL) in organic solar cells is employed. Quantum chemistry calculations and experimental results show that Phen‐NaDPO can interact with SnO2, thereby effectively passivating the surface defects, reducing the work function and improving the electrical conductivity of SnO2, leading to more efficient electron extraction and transport in the organic solar cells (OSCs). Moreover, upon the Phen‐NaDPO modification, the decreased surface energy of SnO2 ETL accounts for enhanced exciton dissociation and charge transport, due to the more ordered molecular organizations of the active layers. Consequently, the inverted OSCs involving Phen‐NaDPO/SnO2 ETLs exhibit an enhanced power conversion efficiency of 17.06% (PM6:Y6) and 18.31% (PM6:L8‐BO), which is the highest efficiency for SnO2 ETL‐based binary solar cells to date. Furthermore, the devices based on Phen‐NaDPO/SnO2 ETL show better device stability (storage stability, photostability and humid stability), with T80 exceeding 200 h encapsulated under light irradiation and 400 h without encapsulation in high‐humidity ambient condition. These results demonstrate that the modification of SnO2 using wide‐band highly stable conjugated small molecules is very promising for simultaneously improve the efficiencies and device stability of OSCs. [ABSTRACT FROM AUTHOR]

Infrared (IR) solar cells are potential optoelectronic devices for boosting the power conversion efficiency (PCE) of conventional photovoltaics (such as pervoskite and silicon solar cells) by broadening the utilization range of the sunlight spectrum to short‐wavelength infrared region. PbSe colloidal quantum dots (QDs) are one of the optimal candidates for IR solar cells because of their tunable bandgap in the IR region and flexible solution processibility. At present, the best PbSe QD IR photovoltaics generally adopt ZnO as an electron transport layer (ETL). However, the intrinsic drawbacks and surface defects of ZnO can potentially deteriorate the PCE of devices. Herein, Ti3C2Tx, a representative 2D transition carbide, is combined with sol‐gel ZnO to develop a new hybrid ETL for fabricating high‐performance IR solar cells. This combination effectively suppresses the defects within ZnO by forming new bondings and simultaneously enhances the crystalline of ZnO film. Meanwhile, the introduction of Ti3C2Tx into ZnO film accelerates the transport and collection of photo‐generated carriers by constructing a new electron transport pathway. Consequently, compared to the bare devices, the infrared PCE of PbSe QD solar cells increases by 19.5% to 1.04%. These results demonstrate that this hybrid ETL can offer a bright approach for developing high‐performance optoelectronic devices. [ABSTRACT FROM AUTHOR]

[Display omitted] The impact of different electron transport layers (ETLs) based on fullerene derivatives, such as the well-known PC 61 BM and promising 3-pyridyl-substituted pyrrolidino[60]fullerene (PYF-30), on the electric field-induced degradation of inverted perovskite solar cells has been demonstrated. Devices assembled using PYF-30 and PC 61 BM deposited from deuterated chloroform exhibit significantly higher stability compared to PC 61 BM films deposited from chlorobenzene. The main reason for the decrease in the efficiency of the device during aging is the formation of pinhole-type defects in the ETL caused by the agglomeration of molecules of fullerene derivatives. [ABSTRACT FROM AUTHOR]

Tin oxide (SnO2) and aluminum-doped zinc oxide (AZO) have been recognized as promising materials for the electron transport layer (ETL) in perovskite solar cells (PSCs) due to their favorable optoelectronic properties and low-temperature deposition processes. However, high surface trap density at the ETL/perovskite interface limits the further improvement of the power conversion efficiency (PCE) of planar PSCs. Herein, we have demonstrated a simple surface treatment of low-temperature deposited SnO2/AZO–ETL through mono-ethanolamine (MEA) to passivate the defects at the AZO/perovskite interface and reduce carrier recombination. Meanwhile, after MEA modification, the defect states at the AZO/perovskite interface were reduced, and the carrier transport capability was improved. PSC based on MEA modification showed an enhanced PCE of 15.73%, compared to 12.66% without MEA treatment, and a fill factor (FF) of 68.30% on a 0.25 cm2 active area. Furthermore, the MEA-passivated device exhibits excellent stability and retains ~ 77% of its initial PCE after 1000 h under ambient storage without encapsulation. Thus, interface engineering based on the mono-ethanolamine passivation provides a feasible and novel strategy to improve the quality of ETL to fabricate high-efficiency planar PSCs. [ABSTRACT FROM AUTHOR]

In recent years, perovskite solar cells (PSCs) have gained major attention as potentially useful photovoltaic technology due to their ever-increasing power-conversion efficiency (PCE). The efficiency of PSCs depends strongly on the type of materials selected as the electron transport layer (ETL). TiO2 is the most widely used electron transport material for the n-i-p structure of PSCs. Nevertheless, ZnO is a promising candidate owing to its high transparency, suitable energy band structure, and high electron mobility. In this investigation, hybrid mesoporous TiO2/ZnO ETL was fabricated for a perovskite solar cell composed of FTO-coated glass/compact TiO2/mesoporous ETL/FAPbI3/2D perovskite/Spiro-OMeTAD/Au. The influence of ZnO nanostructures with different percentage weight contents on the photovoltaic performance was investigated. It was found that the addition of ZnO had no significant effect on the surface topography, structure, and optical properties of the hybrid mesoporous electron-transport layer but strongly affected the electrical properties of PSCs. The best efficiency rate of 18.24% has been obtained for PSCs with 2 wt.% ZnO. [ABSTRACT FROM AUTHOR]

An experimental investigation has been undertaken to explore a variety of properties of organic perovskite solar cells (OPSCs) that are distinct in their photovoltaic response. In this study, OPSCs were constructed using zinc oxide, ZnO and [6,6]-phenylC 6 1 -acid methyl ester, PCBM, as electron transfer materials (ETM), poly(3-hexylthiophene), P3HT, as hole transport material (HTM), and CH3NH3PbIX2 as a photosensitizer, where X is either Cl or I. The structural and optical characteristics of the ETM and HTM layers and the perovskite materials of OPSCs were investigated. The I – V and P – V curves of each solar cell prepared in OPSCs were measured using an integrated cell tester. This comprises a photovoltaic I – V measurement system and a solar simulation system. As a result of these results, the OPSC's performance is evaluated. The calculations in this work suggest that the highest power conversion efficiency (PCE = 6.31%) was achieved in photovoltaic devices using CH3NH3PbI3 as the effective absorber layer and ZnO with PCBM as the ETM layer. At a light intensity of 100 mW/cm2, each OPSC cell was performed. Under the same conditions, the I – V curves were evaluated for each OPSC device. By improving the selection of organic and inorganic active materials in the ETM layer, OPSC performance may be improved. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) incorporating chemical-bath-deposited (CBD) SnO2 layers have garnered considerable attention because they combine high electron mobility and low-temperature processing, affording remarkable photovoltaic performance. However, the acidic conditions of CBD limit its compatibility with front transparent electrodes (FTEs). Herein, cost-effective, thermally stable, and highly transparent nitrogen-doped SnO2 (NTO) FTEs tailored to integrate with CBD-SnO2-based PSCs are developed. By precisely controlling the N dopant content in the magnetron sputtering process, a NTO FTE with a sheet resistance of 38.64 /square, an optical transmittance of 86.17%, a smooth surface morphology (1.2 nm), and mechanical flexibility is obtained. Furthermore, doping N in SnO2 imparts thermal and chemical stability superior to those of conventional Sn-doped In2O3 (ITO) electrodes. Additionally, a well-matched energy band of NTO with a SnO2 electron transport layer (ETL) and homogeneous interfaces is a critical advantage. By implementing this multifaceted strategy using a novel low-cost NTO FTE, CBD-SnO2-based PSCs with elevated open-circuit voltages and energy-barrier-free characteristics are fabricated. A champion power conversion efficiency of 20.43% is achieved, and 93.30% of the initial efficiency is retained even after 3 000 h without encapsulation. This integration of a NTO FTE with a SnO2 ETL paves the way for robust and long-lasting high-performance PSCs. [ABSTRACT FROM AUTHOR]

The optimization of charge transport with electron‐hole separation directed toward specific redox reactions is a crucial mission for artificial photosynthesis. Bismuth vanadate (BiVO4, BVO) is a popular photoanode material for solar water splitting, but it faces tricky challenges in poor charge separation due to its modest charge transport properties. Here, a concept of the external electron transport layer (ETL) is first proposed and demonstrated its effectiveness in suppressing the charge recombination both in bulk and at surface. Specifically, a conformal carbon capsulation applied on BVO enables a remarkable increase in the charge separation efficiency, thanks to its critical roles in passivating surface charge‐trapping sites and building external conductance channels. Through decorated with an oxygen evolution catalyst to accelerate surface charge transfer, the carbon‐encased BVO (BVO@C) photoanode manifests durable water splitting over 120 h with a high current density of 5.9 mA cm−2 at 1.23 V versus the reversible hydrogen electrode (RHE) under 1 sun irradiation (100 mW cm−2, AM 1.5 G), which is an activity‐stability trade‐off record for single BVO light absorber. This work opens up a new avenue to steer charge separation via external ETL for solar fuel conversion. [ABSTRACT FROM AUTHOR]

Due to its high carrier mobility and electron transmission, the phenyl-C61-butyric acid methyl ester (PC61BM) is usually used as an electron transport layer (ETL) in perovskite solar cell (PSC) configurations. However, PC61BM films suffer from poor coverage on perovskite active layers because of their low solubility and weak adhesive ability. In this work, to overcome the above-mentioned shortcomings, 30 nm thick PC61BM ETLs with different concentrations were modeled. Using a 30 nm thick PC61BM ETL with a concentration of 50 mg/mL, the obtained performance values of the PSCs were as follows: an open-circuit voltage (Voc) of 0.87 V, a short-circuit current density (Jsc) of 20.44 mA/cm2, a fill factor (FF) of 70.52%, and a power conversion efficiency (PCE) of 12.54%. However, undesired fine cracks present on the PC61BM surface degraded the performance of the resulting PSCs. To further improve performance, multiple different thicknesses of ZnO interface layers were deposited on the PC61BM ETLs to release the fine cracks using a thermal evaporator. In addition to the pavement of fine cracks, the ZnO interface layer could also function as a hole-blocking layer due to its larger highest occupied molecular orbital (HOMO) energy level. Consequently, the PCE was improved to 14.62% by inserting a 20 nm thick ZnO interface layer in the PSCs. [ABSTRACT FROM AUTHOR]

Cs2TiBr6 materials have promising applications in organic–inorganic halide perovskite solar cells (PSCs), but their power conversion efficiency (PCE) is low. Herein, based on the matching band structure of MASnBr3 and Cs2TiBr6, a no‐electron transport layer (ETL)‐structured laminated PSC is constructed for numerical simulation using SCAPS‐1D. The results have shown that the ETL‐free structure reduces the potential barrier between the interfaces and improves the performance of the device. MASnBr3 is used to replace the traditional hole transport layer to form a laminated structure, which is more conducive to the built‐in electric field of the device. Through exploring the internal influencing factors and applicable environment, it is found that the device can maintain a good operating level between 230 and 430 K. Finally, the best PCE of 19.63% is achieved in the proposed device structure (FTO/Cs2TiBr6/MASnBr3/Au). This work provides a new approach to achieving lead‐free and efficient laminated PSCs in a wide temperature range of usage environments from −43 to 157 °C. [ABSTRACT FROM AUTHOR]

Tin oxide (SnO2) semiconductor is recognized as a highly promising material for the electron transport layer (ETL) in perovskite solar cells (PSC) due to their wide band gap energy and high electron mobility. This material has been considered as the potential alternative material for substituting the conventional titanium dioxide (TiO2). In the form of nanostructure material, it is expected that SnO2 as the ETL in PSC device can be significantly improved owing to its high surface area leading to more intensive photon absorption. In this present study, SnO2 nanoparticles were synthesized via the hydrothermal method with temperature variations ranging from 120 °C to 160 °C for 16 hours. The as-synthesized samples were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), and an ultraviolet-visible (UV-Vis) spectrophotometer. The SnO2 nanoparticles were then integrated into the PSC device as the ETL, and the performance testing was conducted using a semiconductor parameter analyzer to obtain the I-V curve. On the basis of investigation results, it has been found that the temperature used during the hydrothermal process plays a crucial role in determining the crystallinity, morphology, and band gap energy of the SnO2 nanoparticles. The results of the PSC performance test indicate that SnO2 nanoparticles synthesized at a hydrothermal temperature of 150 °C demonstrated the highest power conversion efficiency (PCE) of 3.89 %. This outcome confirms the viability of SnO2 nanoparticles produced through the hydrothermal method. [ABSTRACT FROM AUTHOR]

Numerical simulation can provide an effective theoretical basis for studying carrier transport, collection and diffusion in perovskite solar cells. We used SCAPS-1D software to perform numerical simulations based on CH3NH3Pb(I1−xBrx)3 solar cells. First, we analyzed the thickness of the absorbing layer, doping concentration and defect density, and found that the thickness of 0.5 μm and the defect density of 3 × 1011 cm−3 have great photoelectric conversion performance. We then adjusted the thickness and doping concentration of the hole transport layer to further optimize the P3HT hole transport and diffusion performance. In addition, we found that the interface defect layer has little effect on device performance, but the FTO layer plays an important role in the electron-free layer structure of transmitting electrons. Finally, we compared the electron-transport-layer-free structure with the traditional electron transport layer structure containing PC61BM, SnO2, TiO2 and C60, and predicted the excellent photoelectric conversion performance of the electron-transport-layer-free solar cell structure by 26.15%. Our work simplifies the preparation process of traditional solar cells, providing new insights not only for the development of high-efficiency solar cells, but also for the development of solar cells without electron transport layers. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) with CH3NH3PbX3 (MAPbX3, X = Br, I, Cl) as light-absorbing layer are used as a new generation of low-cost, high-efficiency photovoltaic devices. Compared with other types of photovoltaic devices, this type of cell has the advantages of abundant raw materials, simple process, etc., and its efficiency has risen rapidly from 3.8% to 25.7% in less than 15 years. It is almost comparable to commercial silicon solar cells and has become a new star in the field of energy applications. Normally, zinc oxide (ZnO) has been widely studied as the most important electron transport layer (ETL) of PSCs because of its advantages such as easy processed, high electron mobility, low manufacturing cost, and diverse morphology and structure. In this paper, ETL of ZnO nano film with different structures is taken as the research object, and its application in PSCs is summarized. The research progress of PSCs based on different morphology ZnO nano structures is introduced in detail, and the main problems faced by this type of solar cells are analyzed. In addition, the development trend of this device is proposed. [ABSTRACT FROM AUTHOR]

The field of photovoltaics relies heavily on compound semiconductors, particularly those based on selenium. However, challenges in maintaining stoichiometry and the scarcity of elements like Indium and Gallium hinder their widespread adoption. Tin monoselenide (SnSe) emerges as a promising alternative to silicon, thanks to its favorable properties, including a high absorption coefficient, suitable band gap, and excellent chemical stability. Additionally, SnSe exhibits superior thermal stability and can maintain efficiency under a wider range of operating conditions. Its unique crystal structure allows for enhanced charge carrier mobility, facilitating better performance in thin-film applications. These attributes collectively position SnSe as a highly competitive material in the pursuit of efficient and reliable solar energy solutions. Despite its potential, there is a lack of research on low-efficiency solar cells based on SnSe, highlighting the need for further exploration. Our study advocates for a theoretical investigation into the factors affecting SnSe-based solar cell efficiency, focusing on loss mechanisms like bulk and interface recombination. We propose an analytical model that examines various recombination mechanisms and their interactions to enhance efficiency. Experimental results validate our model, revealing the pivotal role of recombination mechanisms at both bulk and interface levels. Besides, the suggested model is used as a fitness function for the Multi Objective Particle Swarm Optimization (MOPSO) technique to identify the optimal combination of design parameters that produced the highest efficiency. The optimized design with In2O3 and MgZnO as Electron transport layer (ETL) materials surpasses current efficiency limitations and explore efficient Cd-free electron transport layer with suitable band alignment. Overall, our strategy by combining analytical model with optimization technique provides insights and solution for enhancing SnSe-based solar cell efficiency, to exceed 13%. [ABSTRACT FROM AUTHOR]

In order to reduce current leakage and improve electron transfer in solar cells, charge transport layers (CTL), mainly hybrid electron transport layers (h-ETL), are considered as a solution. In this research contribution, computational analysis using SCAPS-1D software is performed to explore the output photovoltaic parameters of a Sb2S3-based solar cell with h-ETL. No theoretical works on this configuration have been previously reported. The main objectives of the present work are to propose a h-ETL with good band alignment with the Sb2S3 absorber, high transparency, and Cd free; to mitigate the instability and cost issues associated with using Spiro-OMeTAD HTL; and to optimize the solar cell. Thus, we calibrated the J - V characteristics and electrical parameters of the FTO/(ZnO/TiO2)/Sb2S3/Spiro-OMeTAD/Au solar cell by numerical simulation and compared them with those of the experiment. Subsequently, our simulations show that to replace the TiO2 ETL used in the experiment and to form the h-ETL with ZnO, IGZO is found to be a good candidate. It has better band alignment with the Sb2S3 absorber than TiO2 ETL, which reduces the trap states at the ETL/Sb2S3 interface; it has high transparency due to its wide bandgap; and an intense electric field is generated at the IGZO/Sb2S3 interface, which reduces the recombination phenomenon at this interface. MoO3, MASnBr3, Cu2O, CuI, and CuSCN HTL were also tested to replace the Spiro-OMeTAD HTL. Simulation results show that the cell with MoO3 HTL achieves higher performance due to its high hole mobility and high quantum efficiency in the visible region; it also allows the solar cell to have better thermal stability (TC = − 0.32 %/K) than the cell with Spiro-OMeTAD HTL (TC = − 0.53 %/K). The parameters that could improve the solar cell efficiency (η) obtained after these substitutions were also optimized. In particular, the parameters of the Sb2S3 absorber layer (thickness, defect density, and doping), ETL and HTL layer thicknesses, h-ETL/Sb2S3 interface defect density, and series and shunt resistances have been optimized. Finally, by combining high performance and thermal stability, the results show that the thermal stability of the solar cell depends on the back contact type; thus, nickel (Ni) was found to combine high performance and better thermal stability among the back contacts investigated. After these improvements, the efficiency of the Sb2S3-based solar cell increased from 5.08% ( J SC = 16.19 mA/cm2, V OC = 0.56 V, and FF = 55.40 %) to 15.43% ( J SC = 18.51 mA/cm2, V OC = 1.11 V, and FF = 74.76 %). This study proposes an approach to optimize the Sb2S3 upper subcell for tandem solar cells. [ABSTRACT FROM AUTHOR]

Pristine fullerene C60 is an excellent electron transport material for state‐of‐the‐art inverted structure perovskite solar cells (PSCs), but its low solubility leaves thermal evaporation as the only method for depositing it into a high‐quality electron transport layer (ETL). To address this problem, we herein introduce a highly soluble bowl‐shaped additive, corannulene, to assist in C60‐assembly into a smooth and compact film through the favorable bowl‐ball interaction. Our results show that not only corannulene can dramatically enhance the film formability of C60, it also plays a critical role in forming C60‐corannulene (CC) supramolecular species and in boosting intermolecular electron transport dynamics in the ETL. This strategy has allowed CC devices to deliver high power conversion efficiencies up to 21.69 %, which is the highest value among the PSCs based on the solution‐processed‐C60 (SP‐C60) ETL. Moreover, the stability of the CC device is far superior to that of the C60‐only device because corannulene can retard and curb the spontaneous aggregation of C60. This work establishes the bowl‐assisted ball assembly strategy for developing low‐cost and efficient SP‐C60 ETLs with high promise for fully‐SP PSCs. [ABSTRACT FROM AUTHOR]

SnO2 is one of the most used inorganic electron transport materials for organic‐inorganic halide perovskite solar cells. However, the surface defects of SnO2 will block the electron transport at the SnO2/perovskite buried interface and limit the device performance. Here, poly(acrylic acid) (PAA) is employed to modify the SnO2 electron transport layer. Carboxyl groups can react with KOH in the commercial SnO2 aqueous colloidal dispersion to produce potassium polyacrylate, the −COO− can combine not only with oxygen and Sn4+ on SnO2, but also can chelate with uncoordinated Pb2+ defects on perovskite. Moreover, carboxyl groups can form a chemical linker between SnO2 and perovskite via the esterification reaction, leading to the reduction of surface hydroxyl group defects of SnO2. The optimal solar cells with PAA modification achieve an enhanced power conversion efficiency of 18.88 % and improved stability. [ABSTRACT FROM AUTHOR]

This study conducted a simulative analysis of different hybrid perovskite solar cells with various hybrid electron transport layers (ETL) and hole transport layers (HTL). The electron transport layer boosts durability, lowers production costs, increases stability, improves light absorption, and increases efficiency. Hybrid ETLs are taken into consideration to improve the device's performance. The selected hybrid ETLs (PCBM–SnS2, TiO2–SnO2, and PCBM–PCPB) were modeled with four hybrid perovskite absorbers (CsPbI3, FAPbI3, MAPbI3, and FAMAPbI3) and five HTLs (PEDOT: PSS, CuI, Spiro-OMeTAD, CBTS, and NiO). Three sets of solar cells are found to be the most effective configurations after investigating over sixty different combinations of perovskite solar cell architectures. The structures show CBTS as the efficient HTL for FAMAPbI3 with all three hybrid ETLs. Besides, a holistic analysis of the effect of several factors such as the defect density and thickness of the absorber layer, temperature, parasitic resistances, capacitance, Mott–Schottky, impedance, conduction band offset, and current density–voltage and quantum efficiency characteristics is performed. The results show a maximum power conversion efficiency of 25.57%, 26.35%, and 23.36% with PCBM–SnS2, TiO2–SnO2, and PCBM–PCPB respectively. Among the studied hybrid ETLs, perovskite solar cell associated with TiO2–SnO2 has depicted a superior performance (Voc = 1.12 V, Jsc = 26.88 mA/cm2, FF = 87.27%). The efficiency of the perovskite solar cell using this study has been drastically enhanced compared to the previous experimental report. The proposed strategy provides a new avenue for attaining clean energy and allows researchers to pave the way for further design optimization to obtain high-performance solar cell devices. [ABSTRACT FROM AUTHOR]

The sufficient material selection of electron transport layer (ETL) enormously promises exceptional conversion efficiency from perovskite (PVT) solar cells (PSCs), which in turn give rise to their rapid establishment in world-wide photovoltaic (PV) market. Among the tactics exerted on ETLs, and thus, intensifies the adequacy of associated PSCs, the methodology of doping stands productive. Therefore, this research validates the implementation of such effectual ETLs on widely approved methyl ammonium lead triiodide (MAPbI 3)–based PSCs. The work brings together two versions of zinc oxide (ZnO) ETLs: one in its pristine form, and the other is aluminum (Al) co-doped with silver (Ag) represented as Ag-AZO. The investigation launches the PV capabilities of Ag-AZO ETL against its undoped correspondent. Accordingly, the earlier part of the investigation centers on the experimental assessment of ZnO and Ag-AZO nanoparticles (NPs) affirming their material and morphological aspects. Later, the research deals with the involvement of both NPs as ETLs signifying the PV potential of MAPbI 3 –based PSCs through comprehensive numerical analysis. The judgements of investigation declare that MAPbI 3 –based PSC with Ag-AZO ETL yields a desirable power conversion efficiency (PCE) of 27.26 % against 25.98 % from the control cell. The investigation will definitely enlighten the development of forthcoming efficient PSCs incorporated with appropriate multiple metals co-doped ETLs. • Ag and Al co-doped ZnO (Ag-AZO) nanoparticles were synthesized using solution process. • The potential of Ag-AZO electron transport layers of perovskite solar cells was validated through numerical analysis. • By applying an Ag-AZO layer, an exceptional efficiency of 27.26 % was accomplished. [ABSTRACT FROM AUTHOR]

• Highly uniform electrodeposited mesoporous TiO 2 as an electron transporting layer for perovskite solar cells. • Impact of high temperature to mesoporous TiO 2 porosity. • Superiority of electrodeposition to traditional spin-coating mesoporous film toward large-area perovskite solar cells. In this study, we present the utilization of electrodeposited TiO 2 mesoporous film (ED-MS-TiO 2) as the electron transport layer (ETL) for perovskite solar cells, especially marking the first report of its application in perovskite solar modules. In the first part of this paper, we refine the electrodeposition process to enhance the porosity of the ED-MS-TiO 2 thin film by elevating the ED temperature from room temperature to a mild 60 °C. Notably, the ED-MS-TiO 2 ETL fabricated at 60 °C demonstrates comparable charge extraction capability and conversion efficiency to the benchmark ETL produced via the widely adopted spin-coating technique, achieving a remarkable 20.5 %. Furthermore, we demonstrate the immense superiority of the ED process in achieving uniformity in the preparation of large-area ETLs. Our current findings reveal that ED-MS-TiO 2 exhibits exceptional uniformity control, with a thickness distribution of 122.69 ± 8.39 nm on a 100 cm² substrate, while its spin-coated counterpart exhibits poor thickness control, measuring 135.72 ± 50.72 nm. Moreover, perovskite solar modules (5 cm × 5 cm) employing the optimized ED-MS-TiO 2 ETL attain an impressive efficiency of 15.63 %, surpassing counterparts utilizing spin-coated TiO 2 ETLs, which achieve only 9.70 %. [ABSTRACT FROM AUTHOR]

SnO2 film is one of the most widely used electron transport layers (ETL) in perovskite solar cells (PSCs). However, the inherent surface defect states in SnO2 film and mismatch of the energy level alignment with perovskite limit the photovoltaic performance of PSCs. It is of great interesting to modify SnO2 ETL with additive, aiming to decrease the surface defect states and obtain well aligned energy level with perovskite. In this paper, anhydrous copper chloride (CuCl2) was employed to modify the SnO2 ETL. It is found that the adding of a small amount of CuCl2 into the SnO2 ETL can improve the proportion of Sn4+ in SnO2, passivate oxygen vacancies at the surface of SnO2 nanocrystals, improve the hydrophobicity and conductivity of ETL, and obtain a good energy level alignment with perovskite. As a result, both the photoelectric conversion efficiency (PCE) and stability of the PSCs based on SnO2 ETLs modified with CuCl2 (SnO2-CuCl2) is improved in comparison with that of the PSCs on pristine SnO2 ETLs. The optimal PSC based on SnO2-CuCl2 ETL exhibits a much higher PCE of 20.31% as compared to the control device (18.15%). The unencapsulated PSCs with CuCl2 modification maintain 89.3% of their initial PCE after exposing for 16 d under ambient conditions with a relative humidity of 35%. Cu(NO3)2 was also employed to modify the SnO2 ETL and achieved a similar effect as that of CuCl2, indicating that the cation Cu2+ plays the main role in SnO2 ETL modification. [ABSTRACT FROM AUTHOR]

Cesium lead iodide (CsPbI3) has attracted a great deal of attention as an absorption layer material for perovskite solar cells (PSCs) with high stability and suitable band gap (1.72 eV). In response to the problems of defect‐induced nonradiative compounding and voltage loss caused by the common perovskite layer, the common strategies of interfacial engineering, altering crystal equivalence, and other modifications involve more complex processes and higher fabrication costs. In order to simplify the process and save costs, this work has omitted the electron transport layer (ETL), while still maintaining a high power conversion efficiency (PCE). This work has simulated PSCs with CsPbI3 (electron transport layer free) and have matched Cu2O as the most suitable hole transport layer (HTL) material. By simulating and optimizing the thickness and defect density of perovskite absorption layer and the defect density of interface defect layer (IDL1, IDL2), and determining the most suitable operating temperature, the PCE of the device can reach 18.8%, which is consistent with the experimental data. The asymmetric effect of the interface defect layer obtained in this work is similar to previous research reports. This research provides an economical solution for high‐performance inorganic perovskite solar cells. [ABSTRACT FROM AUTHOR]

Significant progress has been made in the advancement of perovskite solar cells, but their commercialization remains hindered by their lead-based toxicity. Many non-toxic perovskite-based solar cells have demonstrated potential, such as Cs2AgBi0.75Sb0.25Br6, but their power conversion efficiency is inadequate. To address this issue, some researchers are focusing on emerging acceptor–donor–acceptor'–donor–acceptor (A-DA'D-A)-type non-fullerene acceptors (NFAs) for Cs2AgBi0.75Sb0.25Br6 to find effective electron transport layers for high-performance photovoltaic responses with low voltage drops. In this comparative study, four novel A-DA'D-A-type NFAs, BT-LIC, BT-BIC, BT-L4F, and BT-BO-L4F, were used as electron transport layers (ETLs) for the proposed devices, FTO/PEDOT:PSS/Cs2AgBi0.75Sb0.25Br6/ETL/Au. Comprehensive simulations were conducted to optimize the devices. The simulations showed that all optimized devices exhibit photovoltaic responses, with the BT-BIC device having the highest power conversion efficiency (13.2%) and the BT-LIC device having the lowest (6.8%). The BT-BIC as an ETL provides fewer interfacial traps and better band alignment, enabling greater open-circuit voltage for efficient photovoltaic responses. [ABSTRACT FROM AUTHOR]

The electron transport layer (ETL) has been extensively investigated as one of the important components to construct high-performance perovskite solar cells (PSCs). Among them, inorganic semiconducting metal oxides such as titanium dioxide (TiO2), and tin oxide (SnO2) present great advantages in both fabrication and efficiency. However, the surface defects and uniformity are still concerns for high performance devices. Here, we demonstrated a bilayer ETL architecture PSC in which the ETL is composed of a chemical-bath-deposition-based TiO2 thin layer and a spin-coating-based SnO2 thin layer. Such a bilayer-structure ETL can not only produce a larger grain size of PSCs, but also provide a higher current density and a reduced hysteresis. Compared to the mono-ETL PCSs with a low efficiency of 16.16%, the bilayer ETL device features a higher efficiency of 17.64%, accomplished with an open-circuit voltage of 1.041 V, short-circuit current density of 22.58 mA/cm2, and a filling factor of 75.0%, respectively. These results highlight the unique potential of TiO2/SnO2 combined bilayer ETL architecture, paving a new way to fabricate high-performance and low-hysteresis PSCs. [ABSTRACT FROM AUTHOR]

ZnO semiconductor offers many advantages as an electron transport layer (ETL) in photovoltaic-based devices, including high charge carrier mobility and hole-blocking ability. In this work, ZnO thin film is introduced as an ETL between (Bi 0.93 Gd 0.07)FeO 3 (BFO7Gd) ferroelectric and ITO thin film to form ITO/ZnO/BFO7Gd/Au heterostructure. The device with the ETL exhibited a superior photoresponsivity than the one without ETL, reaching ∼32% enhancement. Furthermore, a subsequent E -field poling on the ITO/ZnO/BFO7Gd/Au heterostructure resulted in an additional ∼25% increase in photoresponsivity. The enhancement is mainly attributed to two factors: (1) high electron mobility and lower recombination rate resulting from the introduction of ZnO ETL, and (2) efficient charge separation facilitated by the polarization-driven internal E field that superimposes with the interfacial built-in E fields. The introduction of ZnO ETL and the utilization of the ferroelectric polarization prove to be an alternative route to further modulate the photosensing performance of BiFeO 3 -based near-UV photodetectors. [ABSTRACT FROM AUTHOR]