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This study uses a sonication method to fabricate a light-harvesting structure on an anatase phase TiO2/1D g-C3N4 nanocomposite electron transport material. In addition, two different metal–organic framework (MOF)-derived porous CuO (CuO-I and CuO-II) are used to modify the carbon electrode. The open atmospheric fabricated TiO2/1D g-C3N4 layer exhibits a maximum power conversion efficiency (PCE) of 6.95% than anatase phase TiO2 (5.40%). Furthermore, the PCE of organometallic perovskite solar cells exhibits 10.03 and 8.43% for CuO-I and CuO-II-modified carbon electrodes. Results reveal that CuO/carbon composite exhibits superior characteristics to commercial carbon electrodes due to increased specific surface area, porosity, and device stability. This dual modification device shows excellent device stability under ambient, thermal, and photostability analysis under AM 1.5 solar irradiation. [ABSTRACT FROM AUTHOR]

In the present work, it is focused to prepare a facile transparent conductive oxide (TCO) material—Magnesium Ortho Stannate (MgSnO3—MTO) as to minimize the shortcomings triggered by the commonly available TCOs. Magnesium acetate and Tin (II) chloride has been taken as the starting materials. In this investigation, magnesium acetate is kept constant and the tin chloride (II) has been increased in the following ratios: (MA:SC taken as 0.1 M:0.1 M-S1A, 0.1 M:0.2 M-S2A, 0.1 M:0.3 M-S3A, 0.1 M:0.4 M-S4A, 0.1 M:0.5 M-S5A). By utilizing Nebulizer Spray Pyrolysis (NSP) technique, the required material is coated onto the glass substrate and the prepared thin film is annealed at 300 °C for three hours. All magnesium tin oxide (MTO) samples exhibit strong (205) diffraction peak of rhombohedral structure of magnesium tin oxide and better crystallinity obtained in the samples S4A and S5A. Besides, this study also analysis the effects of MTO thickness on various physical and opto-electronic properties, including crystallinity, surface morphology, optical transparency, and resistivity. In such, the films of different thicknesses (varied from 310 to 590 nm), crystallinity of the film improved with thinner-to-thin thickness variations. The average visible transmission exceeds80% and the band gap value is 3.65 eV for the sample S5A. FESEM results shows that after annealing grain size has been improved while the molar ratio is increased. Hall Effect studies show the resistivity value is decreased from 10–2 to 10–3 (Ω/cm), while the molar ratio of Tin Chloride (SnCl2) is increased. A comparison of efficiency is performed on Dye Sensitized Solar Cells (DSSC) constructed using various combinations of MTO/MTO photoanodes and counter electrodes. It turns out that DSSC composed of platinum-coated MTO (S5A) as counter electrode and TiO2-coated MTO (S5A) photoanode exhibit superior performance of 2.72% compared to the other cells. [ABSTRACT FROM AUTHOR]

Summary: Carbon‐based perovskite solar cells (PSCs) have exhibited unprecedented progress in the past decades, however, the deficit of open‐circuit voltage and non‐radiative recombination losses are the dominating limiting factors in scaling up the devices in view of commercialization. The researchers and scientists recognize the dominating factors and propose different themes to overcome the limiting factors. Among the different solutions, interfacial engineering of PSCs between the interfaces of transporting layer (electron or hole) and perovskite influences the reduction of non‐radiative recombination losses with improvement in device efficiency. In this work, one‐dimensional (1D) graphitic carbon nitride (g‐C3N4) is synthesized through simple pyrolysis using two different mediums (ethanol and ethylene glycol). 1D g‐C3N4 is interfaced between electron transport layer and perovskite absorber influences effectively in fine‐tuning the work function by aligning the energy level of the fabricated mixed halide PSCs. Nanoscale engineered 1D g‐C3N4 interfacial layer supports boosting the power conversion efficiency of the PSCs to 5.20% and 7.14% for tube and layered tube structures at ambient conditions. Further, the interfacial layer aids in improving thermal (tube: ~59.80%; layered tube: ~74.50%) and photostability (tube: ~78.65%; layered tube: ~87.25%) characteristics of the fabricated devices for 100 h duration at ambient conditions. Highlights: One‐dimensional tubular and layered nanotubes shaped graphitic carbon nitride (1D g‐C3N4) were successfully synthesized.The synthesized 1D g‐C3N4 has been efficiently used as an interfacial layer for the first time.The 1D growth of the tube and layer nanostructured interface modified PSC devices were found to be of excellent charge transfer and charge injection at the (c‐TiO2/perovskite) interface.A maximum PCE of ~7.14% (VOC = 0.532 V, Jsc = 18.23 mA/cm2, and FF = 0.736) was achieved by the introduced 1D g‐C3N4 interlayer resulting in the reduced surface traps on the perovskite layer.A drop in the PCE of just ~20% decrease in its initial PCE value when measured after the period of 100 hours evidencing the thermal stability of the interface modified PSC device compared to that of the bare device. [ABSTRACT FROM AUTHOR]

This study focuses on the fabrication and characterization of Cs2AgBiBr6 double perovskite thin film for field-effect transistor (FET) applications. The Cs2AgBiBr6 thin films were fabricated using a solution process technique and the observed XRD patterns demonstrate no diffraction peaks of secondary phases, which confirm the phase-pure crystalline nature. The average grain sizes of the spin-deposited film were also calculated by analysing the statistics of grain size in the SEM image and was found to be around 412 (± 44) nm, and larger grain size was also confirmed by the XRD measurements. FETs with different channel lengths of Cs2AgBiBr6 thin films were fabricated, under ambient conditions, on heavily doped p-type Si substrate with a 300 nm thermally grown SiO2 dielectric. The fabricated Cs2AgBiBr6 FETs showed a p-type nature with a positive threshold voltage. The on-current, threshold voltage and hole-mobility of the FETs decreased with increasing channel length. A high average hole mobility of 0.29 cm2 s−1 V−1 was obtained for the FETs with a channel length of 30 µm, and the hole-mobility was reduced by an order of magnitude (0.012 cm2 s−1 V−1) when the channel length was doubled. The on-current and hole-mobility of Cs2AgBiBr6 FETs followed a power fit, which confirmed the dominance of channel length in electrostatic gating in Cs2AgBiBr6 FETs. A very high-hole mobility observed in FET could be attributed to the much larger grain size of the Cs2AgBiBr6 film made in this work. [ABSTRACT FROM AUTHOR]

Summary: By the process of doping in semiconducting nanomaterials, properties of the materials such as electronic, optical and photochemical properties can be effectively tuned. Here fluorine doped TiO2 nanostructures were synthesized by microwave assisted solvothermal technique. The X‐ray diffraction patterns (XRD) and Raman analysis results of the sample exhibits peaks characteristic of anatase TiO2. From the UV‐visible absorption analysis, an increase in visible light absorption with no significant change in the absorption edge was noticed. F doped TiO2 nanostructures were found to possess quasi cubic morphology through the transmission electron microscope images and from the presence of well‐defined ring pattern in selected area electron diffraction patterns the polycrystalline nature of the samples were confirmed. The presence of fluorine in the TiO2 lattice was confirmed through the presence of Ti3+ states using X‐ray photoelectron spectroscopy (XPS) analysis and electron paramagnetic resonance (EPR) analysis respectively. The prepared TiO2, F doped TiO2 nanostructures were coated over fluorine doped tin oxide (FTO) substrates, further they were subjected to dye sensitization and were used as photoanodes in dye sensitized solar cells and their power conversion efficiencies were studied. [ABSTRACT FROM AUTHOR]

Summary: Electron transport layer is one of the important layer in the dye‐sensitized solar cells (DSSCs) which is responsible for the transport of photo‐generated electrons by the dye to the outer circuit. TiO2 has been widely used as electron transport material in DSSCs. However, improving the electrical conductivity of TiO2 without sacrificing the surface area is one of the important strategies to improve the efficiency of the DSSCs. Here graphene oxide (GO) is added as an additive into the TiO2 network towards the preparation of TiO2/reduced graphene oxide (RGO) composites by UV assisted photocatalytic reduction method. The RGO/TiO2 composites with different compositions of RGO were characterized and the performance of DSSCs using the prepared material as photoanode was studied. Furthermore, through the D and G band Raman peaks, the reduction of GO to RGO was confirmed. The optical properties of the prepared material were analyzed using UV‐visible spectroscopy and photoluminescence analysis, respectively. The carrier lifetime of the TiO2 and TiO2/RGO composites was studied using time resolved photoluminescence studies. The high‐resolution transmission electron microscope images of prepared TiO2/RGO composites were found to have sheet‐like structure surrounding the near spherical nanoparticles, which could be attributed to that of RGO and TiO2, respectively. The binding energy states of the prepared material were studied using X‐ray photoelectron spectroscopy (XPS) spectra. The incorporation of RGO in TiO2 was found to improve the Brunauer–Emmett–Teller (BET) surface area of TiO2 and distribution of pores in TiO2 and TiO2/RGO composites was found to be uniform. The DSSCs were fabricated using the prepared TiO2 and TiO2/RGO composites as photoanodes and their power conversion efficiencies were analyzed. [ABSTRACT FROM AUTHOR]

Spherical like-Titanium dioxide (TiO2) nanoparticles were synthesized by the green sol-gel method using Plectranthus amboinicus leaf extract for different pH values. The prepared TiO2 nanoparticles have been coated over the Indium tin oxide (ITO) substrate by using the doctor blade approach and the Rose Bengal (RB) organic dye utilized as a sensitizer for all constructed dye-sensitized solar cells (DSSCs). The X-ray diffraction (XRD) endorses the creation of tetragonal crystal structured TiO2 nanoparticles with the anatase phase and the average crystalline size is estimated as 27 nm. Scanning electron microscopy (SEM) micrograph reveals that the nanoparticles are uniformly distributed with spherical like-morphology without agglomeration. UV absorption spectra (UV-Vis) was absorbed to protect the bandgap energy in the range of 3.02–2.95 eV. Fourier transform infrared spectrum (FTIR) was recorded to investigate the presence of chemical composition in synthesized pure TiO2 nanoparticles. The DSSCs assembled for prepared TiO2 nanoparticles have exhibited solar to electrical energy conversion efficiency reached 1.3% by using Plectranthus amboinicus leaf extract under the illumination of 100 mW cm−2. Graphical abstract [ABSTRACT FROM AUTHOR]

To improve the performance of PSCs, it is essential to prevent the carrier recombination losses at the interfaces of the transparent metal oxide electrode/electron transport layer (ETL)/active absorber perovskite layer. This present work reports on the green synthesis approach used for the preparation of flake like-ZnO nanostructure (GF-ZnO NS), naturally extracted from the leaf of Albizia Amara, used as a reducing cum capping agent. Herein, we have introduced an n-type GF-ZnO NS material as an efficient electron transport interfacial layer (bi-ETL) at the ETL/perovskite junction in the fabricated perovskite solar cells (PSCs). The structure of the fabricated PSC device is as follows: glass/ITO/bi-ETL (c-TiO2/GF-ZnO NSs)/CH3NH3PbI3−xClx/spiro-MeOTAD/Au. A comparative study has also been carried out by deploying electron transport materials such as c-TiO2 and GF-ZnO NSs separately. From this, it has been found that the bi-ETL perovskite solar cell devices achieved a maximum power conversion efficiency (PCE) of 7.83% with an open-circuit voltage (VOC) of 0.728 V, a short circuit current density (JSC) of 20.46 mA cm−2 and a fill factor (FF) of 52.61% whereas, the c-TiO2, GF-ZnO NSs and the chemically reduced CR-ZnO ETL based devices achieved a PCE of 4.84%, 5.82% and 6.81%, respectively. The better performance obtained for the bi-ETL based devices is ascribed to the enhanced carrier extraction and the reduced recombination losses at the interface between the ETL and the active perovskite layer. [ABSTRACT FROM AUTHOR]

In the emerging photovoltaic (PV) technologies, the golden triangle rule includes higher efficiency, longevity (or stability), and low cost, which are the foremost criteria for the root of commercial feasibility. Accordingly, a unique low-cost, ecofriendly, all-solution-processed, "bio-inspired" graphitic carbon (extracted from the most invasive plant species of Eichhornia crassipes : listed as one of the 100 most dangerous species by the International Union for Conservation of Nature) and a mixed halide perovskite interface-engineered, unique single-cell large-scale (10 × 10 sq.cm with an active area of 88 cm 2 ) carbon-based perovskite solar cell (C-PSC) are demonstrated for the first time, delivering a maximum PCE of 6.32%. Notable performance was observed under low light performance for the interface-engineered champion device fabricated using the layer-to-layer approach, which, even when tested under fluorescent room light condition (at 200 lux of about ∼0.1 SUN illumination), exhibited a significant PCE. In terms of addressing the stability issues in the fabricated PSC devices, the present work has adopted a two-step strategy: the instability toward the extrinsic factors is addressed by encapsulation, and the subsequent intrinsic instability issue is also addressed through interfacial engineering. Surprisingly, when tested under various stability conditions (STC) such as ambient air, light (continuous 1 SUN, under room light illumination (0.1 SUN) and direct sunlight), severe damp up to a depth of ∼25 mm water (cold (∼15 °C) and hot (∼65 °C)), acidic pH (∼5), and alkaline pH (∼11)) conditions, the fabricated large-scale carbon-based perovskite solar cells (C-LSPSCs) retained unexpected long-term stability in their performance for over 50 days. As to appraise the performance superiority of the fabricated C-LSPSC devices under various aforesaid testing conditions, a working model of a mini-fan has been practically powered and demonstrated.