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Low temperature solution-processed SnO 2 is favorable for electron transport layer (ETL) of flexible perovskite solar cells (PSCs) owing to their process compatibility. Here, we propose a route of condensation reflux-processed SnO 2 ETLs for PSCs using SnCl 2 source. However, the low temperature SnCl 2 -derived SnO 2 ETLs are inherently associated with a high defect state density as well as a large amount of H+ and Cl- residual on the surface, which will cause open-circuit voltage (V OC) loss of the devices. To tackle this issue, aqueous solutions of KOH, CsOH, and KCl have been employed to regulate the buried interfaces. The effects of different cations (K+ and Cs+) and anions (OH- and Cl-) on the photovoltaic performance of the devices have been comparatively explored. The buried interface with KOH modification showed the best effect, which not only improved the quality and light absorption of CsPbBr 3 perovskite layer but also markedly reduced the defect state density at the interface. The optimal device with an architecture of FTO/SnO 2 /KOH/CsPbBr 3 /carbon exhibited a champion power conversion efficiency (PCE) of 7.80 %, V OC of 1.46 V, short-circuit current density (J SC) of 7.50 mA/cm2, and fill factor (FF) of 0.71, compared with the pristine counterpart with a PCE of 5.86 %, V OC of 1.40 V, J SC of 6.37 mA/cm2, and FF of 0.66, respectively. The strategy of low temperature-processed SnO 2 ETLs by KOH interface modification may also provide an avenue for other-typed flexible PSCs manufacture. [Display omitted] [ABSTRACT FROM AUTHOR]

This study delves into the profound implications of employing an intensive xenon lamp treatment with a rapid curing method completed within 4 min, to fabricate a ZnO layer. Subsequently, we applied a coating of PM6:Y6 as the active layer and utilized MoO 3 /Ag as the contact electrode, aiming to advance the efficiency of polymer solar cells (PSCs) through entirely room-temperature processes. Our investigation juxtaposes this xenon lamp treatment with the conventional hot plate method for annealing the ZnO layer, conducted at 180 °C for both 20 min and 4 min. Remarkably, our proposed xenon lamp treatment process not only promotes charge transfer but also exhibits enhancements of the lattice oxygen in the Zn-O layer. This innovative methodology of xenon treatment yields a notable increase in power conversion efficiency (PCE), achieving 14.55 %, compared to 13.71 % and 12.44 % for the ZnO layers annealed with a hot plate for 20 min and 4 min, respectively. Moreover, devices subjected to the 4-min xenon lamp treatment maintained 85 % (T 85) of their original Power Conversion Efficiency (PCE) after enduring 500 h of one-sun aging measurement. These findings evoke optimism regarding the xenon treatment's potential to streamline the fabrication process, and provide a promising avenue for mitigating interface degradation while enhancing the stability of PSCs. [Display omitted] • High-energy pulses generated by xenon reduce the oxygen vacancies in ZnO film. • Xenon stabilizes the active layer of PM6:Y6, reducing trap-assisted recombination. • Xenon treatment boosts incident light capture, increasing J sc and FF in PSCs devices. • Xenon-treated PSCs maintain T 85 stability, surpassing T 45 from hot plate annealing. [ABSTRACT FROM AUTHOR]

• Novel Sr-doped BaTiO 3 ETL enhances perovskite solar cell performance beyond traditional TiO 2 layers. • BST-incorporated PSCs achieve 16.32% efficiency, with potential to reach 28.65% in optimized devices. • FDTD simulations reveal BST's superior optical and electrical properties compared to BTO-based cells. • Findings advance interfacial engineering in PSCs, promising significant improvements in photovoltaic technology. This work investigates the potential of BaTiO 3 (BTO) and Sr-doped BaTiO 3 (BST) as electron transport layers (ETL) in perovskite solar cells (PSCs) through Finite-Difference Time-Domain (FDTD) simulations. A comprehensive analysis was conducted to optimize the thickness of each layer in the PSC structure, with the aim of enhancing the photovoltaic performance and stability. Results indicate that BST-based PSCs exhibit superior optical and electronic properties compared to BTO-based PSCs, achieving higher ultimate efficiency (28.65 %) and power conversion efficiency (16.32 %). This improvement is attributed to better band alignment and higher electron mobility in BST, which enhances charge separation and reduces recombination losses. Optical analysis reveals that BST-based PSCs have a consistently higher spectral response across all wavelengths, indicating more effective light absorption and conversion into electrical current. The external quantum efficiency (EQE) of BST-based PSCs is consistently higher, resulting in an increase in Jsc of 16.87 mA/cm2 compared to 15.96 mA/cm2 for BTO-based cells. These findings highlight the potential of BST as a superior ETL material for high-performance PSCs, offering light management and charge-transport properties improved compared to those of conventional BTO-based ETLs. [ABSTRACT FROM AUTHOR]

As a new and efficient solar cell, perovskite solar cell has attracted wide attention due to its excellent performance. The electron transport layer in perovskite solar cells has a significant impact on device performance. SnO 2 films that can be prepared by solution method have become the first choice for electron transport layer due to their simple process and excellent performance. However, the defects in SnO 2 thin films and non-radiative recombination sites at the SnO 2 /Perovskite interface will lead to potential losses in the performance of photovoltaic devices. Therefore, in order to improve the interface loss and interface characteristics and prepare more efficient perovskite solar cells. In this work, a functional polymer, polyvinyl alcohol (PVA), is introduced to regulate the arrangement of SnO 2 nanocrystals. The SnO 2 -PVA composite electron transport layer not only improves carrier transport, but also further affects the growth of perovskite films. PVA inhibits the agglomeration of tin dioxide particles by adding it to the aqueous solution of tin dioxide. Meanwhile, the oxygen vacancy defects in the SnO 2 layer have also improved. Correspondingly, SnO 2 -PVA-based PSCs can be obtained a maximum efficiency of 23.73 %. Attributed to the strengthened interface binding and the improved perovskite crystallization process, the devices obtain good long-term stability, retaining 90 % of their initial performance after 1000 h operation at their maximum power point under 1 sun illumination. [Display omitted] • A functional polymers PVA is used in p-i-n PSC, and gain a PCE of 23.73 %. • The electronic extraction efficiency and conductivity of SnO 2 are enhanced by PVA. • SnO 2 -PVA-based device presented outstanding stability under 1 sun illumination for over 1000 h. [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]

Significant advances in the performance of organic photovoltaic (OPV) devices can facilitate their use in internet of things applications. However, achieving excellent photostability and high efficiency using stable, efficient OPV devices in indoor settings is considerably difficult. To address this issue, a zinc oxide (ZnO) electron transport layer (ETL) was modified with a self-assembled monolayer of 4-aminobenzoic acid (ABA) in the present study, and the impact of this modification was correlated with the indoor performance of an OPV device with the PM6:L8-BO photoactive layer. The ABA-treated ZnO ETL exhibited a significant reduction in the work function (from 4.51 to 4.04 eV), surface roughness (from 0.201 to 0.177 nm), and hydrophilicity of an indium-tin-oxide electrode; this aided in selectively extracting charge carriers from the device and minimizing trap-assisted recombination losses. Additionally, the ABA treatment of the ZnO ETL considerably enhanced the electron mobility and recombination resistance. It reduced the trap density, thereby enabling the ZnO/ABA-based device to achieve improved performance. Consequently, the ZnO/ABA-based device exhibited a noteworthy 14.68% higher maximum power output than that of the device without any ZnO surface modification under 1000 lx halogen (HLG) illumination ( P _out, max = 354.48 and 309 µ A cm ^−2 , respectively). Moreover, under thermal illumination conditions (1000 lx HLG lighting), the ZnO/ABA-based device sustained ∼74% of its initial power conversion efficiency over 120 h, significantly higher than its ABA-free equivalent (∼55%).

Abstract Tin oxide has made a major breakthrough in high‐efficiency perovskite solar cells (PSCs) as an efficient electron transport layer by the low‐temperature chemical bath deposition method. However, tin oxide often contains pernicious defects, resulting in unsatisfactory performance. Herein, we develop high‐quality tin oxide films via a nitrogen‐doping strategy for high‐efficiency and stable planar PSCs. The aligned energy level at the interface of doped SnO2/perovskite, more excellent charge extraction and reduced nonradiative recombination contribute to the enhanced efficiency and stability. Correspondingly, the power conversion efficiency of the devices based on N‐SnO2 film increases to 23.41% from 20.55% of the devices based on the pristine SnO2. The N‐SnO2 devices show an outstanding stability retaining 97.8% of the initial efficiency after steady‐state output at a maximum power point for 600 s under standard AM1.5G continuous illumination without encapsulation, while less than 50% efficiency remains for the devices based on pristine SnO2. This simple scalable strategy has shown great promise toward highly efficient and stable PSCs.

The methyl ammonium tin iodide (Ch3Nh3SnI3) perovskite nanocrystals have attracted research interest and have become a rising star in the horizon of photovoltaics due to its narrow band gap, wide visible absorption coefficient and environmental friendliness than its lead-based counterpart (Ch3Nh3PbI3) . In this article, a tin based perovskite solar cell with Zinc oxide (ZnO) and Copper Oxide (CuO) as electron transport medium (ETM) and hole transport medium (HTM) was proposed and investigated numerically using a Solar Cell Capacitance Simulator (SCAPS) tool. With appropriate parameters, a short-circuit current density (Jsc) of 27.56 mA/cm2, open-circuit voltage (Voc) of 0.82 V, fill factor (FF) of 59.32 %, and power conversion efficiency (PCE) of 13.41 % are obtained for the initial simulation. By varying the thicknesses of the absorber and electron transport layer, the optimum thicknesses were observed at 0.6 um and 0.3 um for Ch3Nh3SnI3 and ZnO with corresponding PCEs of 14.36 % and 13.42 %. Upon simulation with optimized parameters, a Jsc of 29. 71 mA/cm2, Voc of 0.83 V, FF of 61.23 % and PCE of 15. 10 % were recorded. These values are superior to those obtained without optimization which means that solar cell performance can be improved to some extent by adjusting the perovskite and electron transport layer and also, Ch3Nh3SnI3 Perovskite solar cell (PSC) is a potential environmentally friendly solar cell with considerable efficiency.

We demonstrate the high efficiency of quantum dot light-emitting diodes (QLEDs) that consist of a mixed layer of SnO2 nanoparticles (NPs) and quantum dots (QDs). A stable mixture of SnO2 NPs and QDs is prepared in chlorobenzene and then applied to QLEDs with no separate electron transport layer (ETL). QLEDs with such a simplified structure produce a maximum luminance of 142,855 cd/m2, an EQE of 9.42%, and a current efficiency of 41.18 cd/A that result from the improved charge balance of the mixed layer. This produces one of the best device performances of QLEDs with a non-ZnO inorganic ETL, clearly indicating the remarkable promise of using SnO2 NPs as an inorganic ETL for QLEDs. Moreover, the reduction of fabrication steps in this solution-based process proves advantageous to next-generation display technology.

Tin (IV) oxide is a highly promising electron transport layer (ETL) for lead halide perovskite solar cells due to its high conductivity, transparency, wide band gap, and the possibility of low-temperature processing. Nonetheless, charge carrier recombination processes at the SnO2/perovskite interface diminish the device performance. Here, we demonstrate that SnO2 doping with guanidine hydrochloride (G-SnO2) leads to efficient surface passivation and a larger band offset between the ETL and the perovskite layer, resulting in reduced voltage losses and faster electron transfer. Moreover, G-SnO2 facilitates the growth of highly crystalline perovskite layers. Consequently, a power conversion efficiency of up to 23.48% and a high open-circuit voltage of 1.18 V are obtained in solar cells incorporating the G-SnO2 ETL. These devices also exhibited negligible hysteresis and maintained more than 96% of their initial power conversion efficiency after 1,250 h exposure to the air without encapsulation.

Quantum‐dot light‐emitting diodes (QLEDs) are proposed as one of the most promising candidates for next‐generation displays, but their commercial application is seriously limited due to the poor performance of blue QLEDs (B‐QLEDs). Herein, this work uses Ti3C2Tx nanosheets to tune the work function (WF) of ZnMgO and to engineer the quantum dot (QD)/electron transport layer (ETL) interface. The B‐QLEDs with ZnMgO‐Ti3C2Tx hybrid ETL exhibit a maximum EQE of 15.81% and a remarkable T50 operation lifetime of 3284 h at 100 cd m−2. In addition to that, ultraviolet photoemission spectroscopy and density functional theory calculations both confirm that the addition of Ti3C2Tx to ZnMgO can effectively tune the ZnMgO's work function, further give rise to the reduction of QD/ETL energy barrier, which finally results in the alleviation of charge accumulation at the QD/ETL interface. The findings of interface engineering by Ti3C2Tx not only provide a promising strategy for the application of 2D materials in optoelectronic devices, but also pave the way to construct high‐performance light‐emitting diodes. [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]

A photodiode‐type photodetector with bulk heterojunction is built with an ITO/SnO2/P3HT:PC61BM/MoO3/Al structure. By evaluating SnO2 interfacial layer thicknesses of 15, 19, 22, 26, and 29 nm, the effect of thickness on the photodetector response is investigated. The results show that the carrier extraction can reach saturation at −1 V. In addition, the device with interlayer thickness of 22 nm achieves the lowest dark current density (1.6 × 10−6 A cm−2), highest specific detectivity (1.3 × 1011 Jones), widest linear dynamic range (LDR, 43.7 dB), and fastest response (raising/falling time of 1.81/2.22 μs). Hence, the performance of the organic photodetectors can be greatly improved by adopting the proper thickness of the SnO2 interfacial layer. [ABSTRACT FROM AUTHOR]

The paper presents the investigation of the method of seeding process for the growth of zinc oxide (ZnO) nanorods (NRs) on the glass substrate as an electron transport layer (ETL) for solar cells. The ZnO NRs were grown by using the hydrothermal method. The seeding process was done via average deposition of zinc crystallite on the glass surface, and the process was compared between with and without spin coating technique. The effect of spin coating parameters during seeding phase on the growth of ZnO nanorods was also investigated in this study. It was found that the sample prepared using the unfiltered solution without spin coating in the seeding phase exhibited the densest ZnO NRs layer with the highest absorption coefficient and high crystallinity. [ABSTRACT FROM AUTHOR]

Recently, the simulation of perovskite solar cells (PSCs) via SCAPS-1D has been widely reported. In this study, we adopted SCAPS-1D as a simulation tool for the numerical simulation of lead-free (Pb-free) PSCs. We used methyl ammonium germanium iodide (MAGeI3) as a light absorber, zinc oxysulphide (ZnOS) as an electron transport layer (ETL), and spiro-OMeTAD as a hole transport layer. Further, the thickness of the ZnOS, MAGeI3, and spiro-OMeTAD layers was optimized. The optimal thicknesses of the ZnOS, MAGeI3, and spiro-OMeTAD layers were found to be 100 nm, 550 nm, and 100 nm, respectively. The optimized MAGeI3-based PSCs exhibited excellent power conversion efficiency (PCE) of 21.62%, fill factor (FF) of 84.05%, and Jsc of 14.51 mA/cm2. A fantastic open circuit voltage of 1.77 V was also obtained using SCAPS-1D. We believe that these theoretically optimized parameters and conditions may help improve the experimental efficiency of MAGeI3-based PSCs in the future. [ABSTRACT FROM AUTHOR]

The high performance of perovskite solar cells was produced with the help of an electron transport layer (ETL) and hole transport layer. The film ETL (mesoporous (meso)-TiO2/carbon dot) boosted the efficiency of the perovskite solar cells. A perovskite cell was fabricated by a coating of carbon dot on a meso-TiO2 ETL. The fabricated meso-TiO2/carbon dot-based device has decreased the pin-holes of the perovskite film layer compared to the meso-TiO2-based device, which boosted 3% of the averaged PCE value of the devices. The UV–visible spectroscopy confirmed that the meso-TiO2/carbon dot ETL showed better absorbance, that is, absorbed more incident light than meso-TiO2 ETL to generate higher power conversion efficiency. Coating of carbon dot on meso-TiO2 reduced carrier recombination, and fadeaway of the perovskite film cracks. The X-ray diffraction spectra displayed the removal of the perovskite component after spin-coating of carbon dot to the meso-TiO2 ETL, indicating that the suppression of non-radiative recombination improves the device performance compared to meso-TiO2 ETL. The stability after four weeks on the performance of the device was improved to be 92% by depositing carbon dot on meso-TiO2 ETL compared to the meso-TiO2 ETL-based device (82%). Thus, the high-quality perovskite cell was fabricated by coating carbon dot on a meso-TiO2 ETL, because the electron transport between ETL and perovskite film layer was improved by the injection of electrons from carbon dot. [ABSTRACT FROM AUTHOR]

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Antimony chalcogenide semiconductors have received much attention for serving as promising light harvesters owing to their excellent materials and photoelectric properties. Particularly, Sb2(S,Se)3 alloyed materials share the complementary advantages of Sb2S3 and Sb2Se3, showing a tunable bandgap ranging from 1.1 to 1.7 eV. In Sb2(S,Se)3 solar cells, although Sb2(S,Se)3 absorber material shows a friendly character to the environment, the widely used CdS electron transport layer (ETL) that often affords considerable device efficiencies is not environmental friendly; moreover, CdS often suffers from severe parasitic light absorption due to its relatively narrow band gap of 2.4 eV. Hence, the exploration of Cd‐free or less‐Cd‐based ETLs is urgently needed. Herein, SnO2‐dominated ETLs are carefully designed by optimizing the concentration of SnO2 precursor solutions and spin‐coating cycles, and are further constructed over 8%‐efficient Sb2(S,Se)3 solar cells, together with the effective modification of SnO2/Sb2(S,Se)3 with an ultrathin CdS layer. The morphological and optical–electrical properties of ETLs, the performance of solar cells, and the related charge recombination mechanisms are discussed. The designed SnO2‐dominated ETLs have sharply decreased the use of heavy metal Cd, thereby reducing the risk of environmental pollution. This work provides important enlightenment for designing totally environmentally friendly Sb2(S,Se)3 solar cells. [ABSTRACT FROM AUTHOR]

Even though Fe2O3 is reported as the electron-transporting layer (ETL) in perovskite solar cells (PSCs), its fabrication and defects limit its performance. Herein, we report a Fe2O3 ETL prepared from FeCl3 solution with a dopant Fe3O4 nanoparticle modification. It is found that the mixed solution can reduce the defects and enhance the performance of Fe2O3 ETL, contributing to improved electron transfer and suppressed charge recombination. Consequently, the best efficiency is improved by more than 118% for the optimized device. The stability efficiency of the Fe2O3-ETL-based device is nearly 200% higher than that of the TiO2-ETL-based device after 7 days measurement under a 300 W Xe lamp. This work provides a facile method to fabricate environmentally friendly, high-quality Fe2O3 ETL for perovskite photovoltaic devices and provides a guide for defect passivation research. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) has received extensive attention in the field of photoelectrochemical water splitting (PEC‐WS). However, ZnO has a narrow absorption range for visible light, easy recombination of photogenerated electrons and holes, and slow kinetics of surface water oxidation, limiting its further practical application. In this work, a FTO/TiO2/ZnO/NiO photoanode with a micro‐nano structure is built with ZnO as nanosheet clusters, TiO2 as the electron transport layer, and NiO for forming p‐n heterojunction between NiO and ZnO. This photoanode exhibits a photocurrent density of 1.91 mA/cm2 at 1.23 VRHE, which is three times that of the pure ZnO photoanode (0.65 mA/cm2). The detailed mechanism investigations demonstrate that the introduced TiO2 can reduce the interface defects between ZnO and FTO, and Ti doping to ZnO improves the conductivity, which simultaneously reduces the bottom surface and bulk charge recombination. The constructed p‐n heterojunction further significantly increases the carrier transfer efficiency. [ABSTRACT FROM AUTHOR]

Solar cells based on lead-free perovskite have demonstrated great potential for next-generation renewable energy. The SCAPS-1D simulation software was used in this study to perform novel device modelling of a lead-free perovskite solar cell of the architecture ITO/WS2/CH3NH3SnI3/P3HT/Au. For the performance evaluation, an optimization process of the different parameters such as thickness, bandgap, doping concentration, etc., was conducted. Extensive optimization of the thickness and doping density of the absorber and electron transport layer resulted in a maximum power-conversion efficiency of 33.46% for our designed solar cell. Because of the short diffusion length and higher defect density in thicker perovskite, an absorber thickness of 1.2 µm is recommended for optimal solar cell performance. Therefore, we expect that our findings will pave the way for the development of lead-free and highly effective perovskite solar cells. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) have experienced rapid development in the past period of time, and a record efficiency of up to 25.7% has been yielded. At present, the PSCs with the planar structure are the most prevailing, which not only can significantly simplify the device fabrication process but also reduce the processing temperature. Particularly, the electron transport layer (ETL) plays a critical role in boosting the device performance of planar PSCs. ZnO is a promising candidate as the ETL owing to its high transparency, suitable energy band structure, and high electron mobility. Moreover, ZnO is easy to be processed at a low cost and low energy. This review mainly summarized the recent advances in the application and strategic optimization of ZnO ETL for planar PSCs. The basic properties of ZnO, including energy levels, mobility, processability, trap defects, as well as chemical stability, are clearly clarified. The most available deposition means for preparing ZnO ETLs were also described briefly. Finally, we presented the challenges and guidelines for utilizing ZnO as ETL on efficient planar PSCs. [ABSTRACT FROM AUTHOR]

A hybrid tin-based perovskite solar cell with p-i-n inverted structure is modeled and simulated using SCAPS. The inverted structure is composed of PEDOT:PSS (as hole transport layer—HTL)/GA 0.2 FA 0.78 SnI 3 -1% EDAI 2 (as perovskite absorber layer)/C60-fullerene (as electron transport layer—ETL). Previous experimental studies showed that unlike conventional tin-based perovskite solar cells (PSC), the present hybrid tin-based PSC passes all harsh standard tests and generates a power conversion efficiency of only 8.3 % . Despite the high stability that this material exhibits, emphasis on enhancing its power conversion efficiency (PCE) is crucial. To that end, various ETL and HTL materials have been rigorously investigated. The impact of energy level alignment between HTL/absorber and absorber/ETL interfaces have been elucidated. Moreover, the thickness and the doping concentration of all the previously mentioned layers have been varied to inspect their effect on the photovoltaic performance of the PSC. The optimized structure with CuI (copper iodide) as HTL and ZnOS (zinc oxysulphide) as ETL scored a PCE of 26 % , which is more than three times greater than the efficiency of the initial structure. The current numerical simulation on GA 0.2 FA 0.78 SnI 3 -1% EDAI 2 could greatly increase its chance for commercial development. [ABSTRACT FROM AUTHOR]

SnO₂ is a widely used electron transport layer (ETL) material in perovskite solar cells (PSCs), and its design and optimization are essential for achieving efficient and stable PSCs. In this study, the in situ formation of a chain entanglement gel polymer electrolyte is reported in an aqueous phase, integrated with SnO₂ as the ETL. Based on the self-polymerization of 3-[[2-(methacryloyloxy)ethyl]dimethylammonium]propane-1-sulfonic acid (DAES) in an aqueous environment, combining the catalytic effect of LiCl (as a Lewis acid) with the salting-out effect, and the introduction of polyvinylpyrrolidone (PVP) as the other polymer chain, a chain entanglement gelled SnO 2 (G-SnO 2 ) structure is successfully constructed with a wide range of functions. The PDEAS-PVP chain entanglement gel achieves passivation and Pb 2 ⁺ capture through chemical chelation mechanisms is explored. The results demonstrated that the all-in-air prepared PSC based on G-SnO 2 exhibited an excellent power conversion efficiency (PCE) of 24.77% and retained 83.3% of their initial efficiency after 2100 h of air exposure. Additionally, the PDEAS-PVP exposes more C═O and S═O active sites, significantly enhanced the lead absorption capability of the PSCs., (© 2025 Wiley‐VCH GmbH.)

Tin oxide (SnO 2 ) is extensively employed as the electron transport layer (ETL) for perovskite solar cells, but the presence of unsaturated Sn dangling bonds and oxygen vacancy defects at surface hinders effective carrier transport. Herein, we present an effective strategy for constructing a hybrid ETL by doping ZnF 2 into the SnO 2 , effectively addressing the oxygen vacancy defects at both the bulk and interface of SnO 2 , thus markedly minimizing nonradiative recombination losses. Additionally, the process-induced strong bonding between F and Sn atoms facilitates the establishment of electron transfer pathways, leading to an increased electron cloud density within SnO 2 and enhanced electron transfer capability, thus further suppressing charge accumulation at the interface. The hybrid ETL strategy can be adaptable to perovskites with various cations. The MAPbI 3 and Cs 0.1 FA 0.9 PbI 3 perovskite solar cells achieved remarkable PCEs of 21.31% and 24.91%, respectively. Moreover, the hybrid ETL design significantly enhances device stability. After 600 h of ambient storage, the unencapsulated optimized devices retained approximately 90% of their initial efficiency.

In fabricating high-efficiency all-perovskite tandem solar cells (APTSCs) with a p-i-n configuration, the electron transport layer (ETL) plays a critical role in facilitating the transport of photogenerated electrons from the front cell to the recombination layer and protecting the front cell from damage during rear cell fabrication. This study introduces aluminum-doped In 2 O 3 (AIO) films grown by atomic layer deposition (ALD) as a promising ETL for high-efficiency APTSCs. ALD-grown AIO films with an optimized Al concentration exhibit superior charge transport characteristics, excellent transparency, and damage-resistant barrier properties against solution infiltration compared with conventional SnO 2 ETLs and undoped ALD In 2 O 3 . Using an ALD SnO 2 /3 at.% AIO bilayer as the electron transport layer, an efficiency of 18.33% is achieved from single-junction wide bandgap perovskite solar cells. Furthermore, the use of ALD SnO 2 /3 at.% AIO ETL enables the reliable fabrication of APTSCs with negligible solution damage to the front cell and minimized power loss. Consequently, APTSC employing the ALD AIO-based ETL exhibit an excellent photoconversion efficiency of 25.46%, outperforming APTSCs with the ALD SnO 2 ETL., (© 2024 Wiley‐VCH GmbH.)

An electron transport layer (ETL) for highly efficient perovskite solar cells (PSCs) should exhibit superior electrical transport properties and have its band levels aligned with interfacing layers to ensure efficient extraction of photo-generated carriers. Nitrogen-doped TiO 2 (TiO 2 :N) is considered a promising ETL because it offers higher electrical conductivity compared to conventional ETLs made from spray-pyrolyzed TiO 2 . However, the application of highly doped TiO 2 :N in PSCs is often limited by the misalignment of energy band levels with adjacent layers and reduced optical transparency. In this study, a novel approach is introduced to enhance the charge transport characteristics and accurately align the electronic band alignment of TiO 2 :N layer through nanoscale doping level grading, achieved through the pulsed laser deposition (PLD) technique. The TiO 2 :N ETL with a graded doping profile can combine characteristics of both highly doped and lightly doped phases on each side. Furthermore, a nanoscale doping gradation, employing an ultrathin sub-layer structure with graded doping levels, creates a smoothly cascading band-level alignment that bridges the adjacent layers, enhancing the transport of photo-generated carriers. Consequently, this method leads to a substantial increase in the power conversion efficiency (PCE), exceeding 22%, which represents a relative improvement of 11% compared to traditional spray-pyrolyzed TiO 2 -based PSCs., (© 2024 The Author(s). Small published by Wiley‐VCH GmbH.)

An appropriate electron transport layer (ETL) or cathode buffer layer (CBL) is critical for high-performance perovskite solar cells (PVSCs). In this work, tetrabutylammonium hydroxide (TBAOH)-functionalized Ti 3 C 2 T x MXene (TBAOH-Ti 3 C 2 T x ) is developed to improve the photovoltaic performance of PVSCs. TBAOH-Ti 3 C 2 T x is synthesized by HF etching and then TBAOH intercalation, and TBAOH can effectively attach to the Ti 3 C 2 T x surface during the intercalation process. In hole transport material (HTM)-free carbon-based PVSCs with the structure of ITO/ETL/MAPbI 3 /carbon, the SnO 2 doped by TBAOH-Ti 3 C 2 T x (SnO 2 :TBAOH-Ti 3 C 2 T x ) as ETL shows decreased WF and increased conductivity and improves the growth of the perovskite film with a larger grain and significantly reduced defects, which synergistically facilitate charge transport and extraction and reduce charge recombination. The HTM-free carbon-based PVSC with SnO 2 :TBAOH-Ti 3 C 2 T x ETL exhibits a significantly higher PCE of 14.93% with enhanced device stability compared to the control device with pristine SnO 2 ETL (11.95%) and also outperforms most of the HTM-free carbon-based PVSCs with MAPbI 3 perovskite reported so far. In traditional inverted PVSCs with the structure of ITO/PTAA/MAPbI 3 /PCBM/CBL/Ag, the TBAOH-Ti 3 C 2 T x is utilized as a CBL to significantly enhance device performance with a high PCE of 21.16%, which is obviously superior than that (16.26%) of the control device without CBL. The impressive results indicate that tetrabutylammonium hydroxide-functionalized Ti 3 C 2 T x MXene possesses great application potential in different functional layers for high-performance PVSCs.

In order to enhance the overall efficiency of colloidal quantum dots solar cells, it is crucial to suppress the recombination of charge carriers and minimize energy loss at the interfaces between the transparent electrode, electron transport layer (ETL), and colloidal quantum dots (CQDs) light-absorbing material. In the current study, ZnO/SrTiO 3  (STO), ZnO/WO 3  (TO), and ZnO/Zn 2 SnO 4  (ZTO) bilayers are introduced as an ETL using a spin-coating technique. The ZTO interlayer exhibits a smoother surface with a root-mean-square (RMS) value of ≈ 3.28 nm compared to STO and TO interlayers, which enables it to cover the surface of the ITO/ZnO substrate entirely and helps to prevent direct contact between the CQDs absorber layer and the ITO/ZnO substrate, thereby effectively preventing efficient charge recombination at the interfaces of the ETL/CQDs. Furthermore, the ZTO interlayer possesses superior electron mobility, a higher visible light transmission, and a suitable energy band structure compared to STO and TO. These characteristics are advantageous for extracting charge carriers and facilitating electron transport. The PbS CQDs solar cell based on the ITO/ZnO/ZTO/PbS-FABr/PbS-EDT/NiO/Au device configuration exhibits the highest efficiency of 15.28%, which is significantly superior than the ITO/ZnO/PbS-FABr/PbS-EDT/NiO/Au solar cell device (PCE = 14.38%). This study is anticipated to offer a practical approach to develop ultrathin and compact ETL for highly efficient CQDSCs., (© 2024 Wiley‐VCH GmbH.)

In this work, the use of poly [(9,9-bis (30- (N,N-dimethylamino) propyl) -2,7-fluorene) -alt-2,7- (9,9-dioctylfluorene) (PFN) as electron transport layer (ETL) in inverted small molecule solar cells (SM-iOSCs) is analyzed. The optical and electrical characteristics obtained are compared with those obtained for similar SM-iOSCs where the ETL was zinc oxide. The p-DTS(FBTTh2)2 and PC70BM materials are used as donor and acceptor in the bulk heterojunction active layer, respectively for all devices. The photovoltaic devices exhibited a power conversion efficiency of 6.75% under 1 sun illumination. Impedance measurements were used to understand the causes that dominate the performance of the devices. We found that the loss resistance is governed by the PFN layer, which results in a lower fill factor value. Studies of atomic force microscopy, external quantum efficiency, and absorption UV-vis on the active layer have been performed to understand the effects of the charge transport dynamics on the performance of the devices.

Improving morphological and electronic properties of the electron transport layer (ETL) is a critical issue to fabricate highly efficient perovskite solar cells. Tin dioxide is used as an ETL for its peculiarities such as low-temperature solution-process and high electron mobility and several handlings have been tested to increase its performances. Herein, SnO2:ZnO and SnO2:In2O3 composites are studied as ETL in planar n-i-p CH3NH3PbI3 solar cells fabricated in ambient air, starting from glass/ITO substrates. Morphological, electrical and optical properties of zinc- and indium-oxide nanoparticles (NPs) are investigated. First-principle calculations are also reported and help to further explain the experimental evidences. Photovoltaic performances of full devices show an improvement in efficiency for SnO2:In2O3–based solar cells with respect to pristine SnO2, probably due to a suppression of interfacial charge recombination between ITO/ETL and ETL/perovskite. Moreover, a better homogeneity of SnO2:In2O3 deposition with respect to SnO2:ZnO composites, conducts an increase in perovskite grain size and, consequently, the device performances.

Abstract Suitable electron transport materials bearing good interfacial contact, improved electron transport ability, and matched energy levels are indispensable for developing efficient perovskite solar cells (PSCs). Herein, regular (n‐i‐p) planar Cs0.05FA0.83MA0.12PbI2.55Br0.45 (CsFAMA) PSC devices were fabricated using a pyridine‐functionalized fullerene derivative (C60‐3‐BPy) as an independent electron transport layer (ETL), delivering a decent power conversion efficiency (PCE) of 18.22%, which is dramatically higher than that of the control device based on [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) ETL (15.70%). The energy level offset between C60‐3‐BPy and the perovskite is smaller than that based on PCBM ETL, which is beneficial for efficient ohmic contact in ETL/perovskite interface and improved open‐circuit voltage (Voc). Moreover, C60‐3‐BPy affords strong coordination interactions with perovskite, leading to an improved film quality of the perovskite layer with enlarged grain size and decreased trap state density, which contribute to facilitated electron extraction as reflected by the increases of both the fill factor (FF) and the short‐circuit current (Jsc). C60‐3‐BPy‐facilitated electron extraction further results in hysteresis‐free devices.

Tungsten oxide (WOx) thin films were synthesized through the RF magnetron sputtering method by varying the sputtering power from 30 W to 80 W. Different investigations have been conducted to evaluate the variation in different morphological, optical, and dielectric properties with the sputtering power and prove the possibility of using WOx in optoelectronic applications. An Energy Dispersive X-ray (EDX), stylus profilometer, and atomic force microscope (AFM) have been used to investigate the dependency of morphological properties on sputtering power. Transmittance, absorbance, and reflectance of the films, investigated by Ultraviolet-Visible (UV-Vis) spectroscopy, have allowed for further determination of some necessary parameters, such as absorption coefficient, penetration depth, optical band energy gap, refractive index, extinction coefficient, dielectric parameters, a few types of loss parameters, etc. Variations in these parameters with the incident light spectrum have been closely analyzed. Some important parameters such as transmittance (above 80%), optical band energy gap (~3.7 eV), and refractive index (~2) ensure that as-grown WOx films can be used in some optoelectronic applications, mainly in photovoltaic research. Furthermore, strong dependencies of all evaluated parameters on the sputtering power were found, which are to be of great use for developing the films with the required properties. [ABSTRACT FROM AUTHOR]

Recently, the design and fabrication of lead (Pb)-free perovskite or perovskite-like materials have received great interest for the development of perovskite solar cells (PSCs). Manganese (Mn) is a less toxic element, which may be an alternative to Pb. In this work, we explored the role of NH3(CH2)2NH3MnCl4 perovskite as a light absorber layer via SCAPS-1D. A Pb-free PSC device (FTO/TiO2/NH3(CH2)2NH3MnCl4/spiro-OMeTAD/Au) was simulated via SCAPS-1D software. The simulated Pb-free PSCs (FTO/TiO2/NH3(CH2)2NH3MnCl4/spiro-OMeTAD/Au) showed decent power conversion efficiency (PCE) of 20.19%. Further, the impact of the thickness of absorber (NH3(CH2)2NH3MnCl4), electron transport (TiO2), and hole-transport (spiro-OMeTAD) layers were also investigated. Subsequently, various electron transport layers (ETLs) were also introduced to investigate the role of ETL. In further studies, an NH3(CH2)2NH3MnCl4-based PSC device (FTO/TiO2/NH3(CH2)2NH3MnCl4/spiro-OMeTAD/Au) was also developed (humidity = ~30–40%). The fabricated PSCs displayed an open circuit voltage (Voc) of 510 mV with a PCE of 0.12%. [ABSTRACT FROM AUTHOR]

This contribution demonstrates the effects of mole ratio, concentration of perovskite components and fullerene derivatives used as electron transport layer (ETL) on the stability and performances of inverted perovskite solar cells (PSCs). C60, C70, PC61BM and PC71BM are selected as ETL materials. Methylammonium iodide (MAI):Lead (II) iodide (PbI2):Lead(II) chloride (PbCl2) are used to form MAPb2I2Cl which is a mixed halogen perovskite structure. The fabricated perovskite device containing PCBM with optimized concentration and mole ratio gives high power conversion efficiency (PCE) of 9.07% with an open-circuit voltage (Voc) of 0.91V, short circuit current density of 14.1mA/cm², and fill factor of 0.71. The lifetime characteristics and the stability are found significantly dependent on the fullerene type. The devices containing PC61BM and PC71BM are able to maintain 50% and 30% of its initial performances, respectively, even after 1100 hours. Overall, the obtained results represent an important step understanding the impacts on the p-i-n type perovskite lifetimes. [ABSTRACT FROM AUTHOR]

Organic solar cells with biological/metalâ€"oxide electron transport layers (ETLs), consisting of a ZnO compact layer covered by a thin DNA layer, both of which deposited with green solvents (water or water/alcohols mixtures) are presented for application under low intensity indoor lighting. Under white LED lamp (200, 400 lx), photovoltaic cells with P3HT:PC70BM polymer semiconductor blends delivered an average maximum power density (MPD) of 8.7 ÎĽ W cmâˆ'2, corresponding to a power conversion efficiency, PCE, of = 8.56% (PCE of best cell was 8.74%). The ZnO/DNA bilayer boosted efficiency by 68% and 13% in relative terms compared to cells made with DNA-only and ZnO-only ETLs at 400 lx. Photovoltaic cells with ZnO/DNA composite ETLs based on PTB7:PC70BM blends, that absorb a broader range of the indoor lighting spectrum, delivered MPDs of 16.2 ÎĽ W cmâˆ'2 with an estimated average PCE of 14.3% (best cell efficiency of 15.8%) at 400 lx. The best efficiencies for cells fabricated on flexible plastic substrates were 11.9% at 400 lx. This is the first report in which polymer photovoltaics incorporating biological materials have shown to increment performance at these low light levels and work very efficiently under indoor artificial light illumination. The finding can be useful for the production of more bio-compatible photovoltaics as well as bio-sensing devices based on organic semiconductors. [ABSTRACT FROM AUTHOR]

All-polymer solar cells (all-PSCs) are organic solar cells in which both the electron donor and the acceptor are polymers and are considered more promising in large-scale production. Thanks to the polymerizing small molecule acceptor strategy, the power conversion efficiency of all-PSCs has ushered in a leap in recent years. However, due to the electrical properties of polymerized small-molecule acceptors (PSMAs), the FF of the devices is generally not high. The typical electron transport material widely used in these devices is PNDIT-F3N, and it is a common strategy to improve the device fill factor (FF) through interface engineering. This work improves the efficiency of all-polymer solar cells through interfacial layer engineering. Using PDINN as the electron transport layer, we boost the FF of the devices from 69.21% to 72.05% and the power conversion efficiency (PCE) from 15.47% to 16.41%. This is the highest efficiency for a PY-IT-based binary all-polymer solar cell. This improvement is demonstrated in different all-polymer material systems. [ABSTRACT FROM AUTHOR]

The efficiency and stability of perovskite solar cells (PSCs) depend not only on the perovskite film quality, but they are also influenced by the charge carriers of both the electron and hole transport layers (ETL and HTL). Doping of the carrier transport layers is considered one of effective technique applied to enhance the efficiency and performance of the PSCs. FK209 cobalt TFSI and lithium TFSI salt were investigated as dopants for mesoporous TiO2 (M-TiO2) in the ETL. Herein, FK209 cobalt doping offers improved conductivity, reproducibility and stability compared to other doping or undoped M-TiO2 control device. It has been found that an optimum concentration of 2.5 mg FK209 cobalt in the M-TiO2 has resulted in an efficiency of 15.6% on 0.36 cm2 active device area, whereas, the undoped M-TiO2 yielded an average efficiency of 10.8%. The enhanced efficiency is due to the improved conductivity of the ETL while maintaining high transparency and low surface roughness with FK209 doping. The M-TiO2 doped with FK209 has a transparency of the 90% over the visible range and its measured energy gap was 3.59 eV. Perovskite films deposited on the M-TiO2 doped with FK209 has also a lower PL intensity indicating faster charge extraction. The measured lifetime of the perovskite films deposited on the optimised M-TiO2 film was 115.8 ns. [ABSTRACT FROM AUTHOR]

We demonstrate the high efficiency of quantum dot light-emitting diodes (QLEDs) that consist of a mixed layer of SnO2 nanoparticles (NPs) and quantum dots (QDs). A stable mixture of SnO2 NPs and QDs is prepared in chlorobenzene and then applied to QLEDs with no separate electron transport layer (ETL). QLEDs with such a simplified structure produce a maximum luminance of 142,855 cd/m2, an EQE of 9.42%, and a current efficiency of 41.18 cd/A that result from the improved charge balance of the mixed layer. This produces one of the best device performances of QLEDs with a non-ZnO inorganic ETL, clearly indicating the remarkable promise of using SnO2 NPs as an inorganic ETL for QLEDs. Moreover, the reduction of fabrication steps in this solution-based process proves advantageous to next-generation display technology. [ABSTRACT FROM AUTHOR]

The light-soaking effect is one of the major drawbacks for inverted organic solar cells (OSCs) if metal oxides are used as the electron transport layer (ETL). The oxide ETL primarily originates the above effect from the energy barrier, deep level defects, and excess carriers tunneling. Here, electron-beam evaporated high-quality pristine and post-treated e-ZnO thin films are utilized to fabricate inverted OSC as the ETL between the transparent cathode and active bulk-heterojunction PBDB-T-2Cl:PC61BM layer to study the influence on device performance. Various experimental techniques, including AFM, XRD, XPS, and UPS, are utilized to identify the surface and semiconducting properties of differently treated interfacial e-ZnO films precisely. XPS results reveal the variation of oxygen vacancies and adsorbed oxygen species on the surface of e-ZnO layers. The semiconducting nature of various e-ZnO thin films for the use of ETL are also probed with the help of UPS results, which accurately locate the valence band maximum and Fermi level position. After correlating the property of e-ZnO systematically with the respective OSC device performance, it is found that the deeper valence band top and higher n-type nature of e-ZnO is desirable to depict the light soaking free highest solar cell efficiency and large open-circuit voltage of about 0.97 V in a single junction. The presence of lesser chemisorbed oxygen species over the e-ZnO surface might be an added advantage to demonstrate the light soaking free operation in inverted OSC devices. [ABSTRACT FROM AUTHOR]

As an electron transport layer (ETL) for organic solar cells (OSCs), a naphthalene diimide (NDI)-based alcohol-soluble small molecule electrolyte (FN-NDI-Br) was designed and synthesized. The small molecule electrolyte was synthesized from the quaternization of the amino-terminal group in the alkyl chain. A bulk heterojunction (BHJ)-based inverted OSCs with the ITO/ZnO/ETL/PTB7-Th:PC71BM/MoO3/Ag structure were fabricated. The power conversion efficiency (PCE) enhancement was achieved by inserting a small molecule electrolyte as the interlayer. The device performance of the device with the PTB7-Th and PC71BM blend as the photoactive layer and FN-NDI with acetic acid additive as ETL was enhanced over the device with pristine ZnO from 8.53% to 8.78%. The performance of the device was enhanced up to 9.16% by modifying the side chain functionality compared with the device with a FN-NDI interlayer. [ABSTRACT FROM AUTHOR]

The metal oxides with low trap density of states as the electron transport layer are crucial for the high performance of the organic solar cells (OSCs). It is universally acknowledged that modifying n-type metal oxide contacts with polymer donors will harm the carrier extraction on account of the mismatched energy level. However, we find that modifying interlayer consisting of the alcohol amines with some polymer donor additive can unusually enhance the performance of the OSCs. Compared with triethanolamine (TEA) passivated ZnO, TEA:polymer donor treated ZnO shows lower trap density and enhances electron mobility resulting in higher current density in OSC devices. Here, we reveal that the enhanced oxygen-defect passivation ability of TEA with polymer additive is attributed to the enhanced negative electrostatic potential of TEA owing to the hydrogen bond formation between the polymer and the hydroxyl group in TEA. This strategy that enhancing the negative electrostatic potential of the passivators for improving oxygen defect passivation can be extended to other types of organic electronic devices. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) are a promising area of research among different new generations of photovoltaic technologies. Their manufacturing costs make them appealing in the PV industry compared to their alternatives. Although PSCs offer high efficiency in thin layers, they are still in the development phase. Hence, optimizing the thickness of each of their layers is a challenging research area. In this paper, we investigate the effect of the thickness of each layer on the photoelectric parameters of n-ZnO/p-CH3NH3PbI3/p-NiOx solar cell through various simulations. Using the Sol–Gel method, PSC structure can be formed in different thicknesses. Our aim is to identify a functional connection between those thicknesses and the optimum open-circuit voltage and short-circuit current. Simulation results show that the maximum efficiency is obtained using a perovskite layer thickness of 200 nm, an electronic transport layer (ETL) thickness of 60 nm, and a hole transport layer (HTL) thickness of 20 nm. Furthermore, the output power, fill factor, open-circuit voltage, and short-circuit current of this structure are 18.9 mW/cm2, 76.94%, 1.188 V, and 20.677 mA/cm2, respectively. The maximum open-circuit voltage achieved by a solar cell with perovskite, ETL and HTL layer thicknesses of (200 nm, 60 nm, and 60 nm) is 1.2 V. On the other hand, solar cells with the following thicknesses, 800 nm, 80 nm, and 40 nm, and 600 nm, 80 nm, and 80 nm, achieved a maximum short-circuit current density of 21.46 mA/cm2 and a fill factor of 83.35%. As a result, the maximum value of each of the photoelectric parameters is found in structures of different thicknesses. These encouraging results are another step further in the design and manufacturing journey of PSCs as a promising alternative to silicon PV. [ABSTRACT FROM AUTHOR]

Flexible and printed perovskite solar cells (PSCs) fabricated on lightweight plastic substrates have many excellent potential applications in emerging new technologies including wearable and portable electronics, the internet of things, smart buildings, etc. To fabricate flexible and printed PSCs, all of the functional layers of devices should be processed at low temperatures. Tin oxide is one of the best metal oxide materials to employ as the electron transport layer (ETL) in PSCs. Herein, the synthesis and application of SnO2 quantum dots (QDs) to prepare the ETL of flexible and printed PSCs are demonstrated. SnO2 QDs are synthesized via a solvothermal method and processed to obtain aqueous and printable ETL ink solutions with different QD concentrations. PSCs are fabricated using a slot-die coating method on flexible plastic substrates. The solar cell performance and spectral response of the obtained devices are characterized using a solar simulator and an external quantum efficiency measurement system. The ETLs prepared using 2 wt% SnO2 QD inks are found to produce devices with a high average power conversion efficiency (PCE) along with a 10% PCE for a champion device. The results obtained in this work provide the research community with a method to prepare fully solution-processed SnO2 QD-based inks that are suitable for the deposition of SnO2 ETLs for flexible and printed PSCs. [ABSTRACT FROM AUTHOR]