Binary Oxide Ceramics (TiO2, ZnO, Al2O3, SiO2, CeO2, Fe2O3, and WO3) for Solar Cell Applications: A Comparative and Bibliometric Analysis

Photovoltaics literature survey (no. 149)

Over 15% efficient wide-band-gap Cu(In,Ga)S2 solar cell: Suppressing bulk and interface recombination through composition engineering

Sputtered transparent electrodes for optoelectronic devices: Induced damage and mitigation strategies

As the world’s energy demand continues to grow, thin-film solar cells are poised to play an increasingly important role in meeting that demand. In this research, we have proposed and simulated a high-efficiency Cu2SnSe3- based thin film solar cell structure using a solar cell capacitance simulator (SCAPS-1D) software. The numerical performance of Cu2SnSe3 thin films solar cell with ZnO:Al as the electron transport layer (ETL), ZnSe as the buffer layer, SnS as the hole transport layer (HTL), Ag as the front and Ni as the back contact with the structure (Ag/ZnO:Al/Cu2SnSe3/SnS/Ni) has been studied. This simulation intended to investigate the effect of the ZnO:Al electron transport layer and SnS hole transport layer on the performance of the proposed solar cell. The device was optimized concerning the thickness, temperature, series and shunt resistance, donor density of the Electron transport layer, back contact metal work function, and acceptor density of the Cu2SnSe3-based thin film solar cell. The thickness of the ETL, buffer, absorber, and HTL was optimized to 0.2 μm, 0.05 μm, 1.5 μm, and 0.1 μm, respectively. The proposed cadmium-free Cu2SnSe3 thin films solar cell exhibited a conversion efficiency of 31.04%, VOC of 1.08 V, JSC of 34.11 mA/cm2, and FF of 83.84%. As a result, due to its low cost, earth-abundant, non-toxicity, and high efficiency, the suggested Cu2SnSe3-based solar cell may be an attractive candidate for thin film solar cells.

Tin oxide (SnOx) as a functional layer, such as electron transport layer (ETL) or buffer layer, is widely used in perovskite solar cells (PSCs). However, SnOx prepared by spin coating is not suitable to be applied to the solar cells with large area or rough substrates. In this paper, SnOx thin films served as the ETL of PSCs were prepared using a simple reactive thermal evaporation (RTE) method, and a convenient ultraviolet ozone treatment (UV‐O3) at room temperature was carried out to replace the common post‐annealing process. The SnOx ETL prepared by RTE is suitable for substrates with arbitrary morphology, and the performance of the PSCs can be improved significantly after the ultraviolet ozone treatment of the SnOx layer. A power conversion efficiency (PCE) up to 20.62% was achieved on the planar PSCs with the RTE SnOx serving as the ETL. Conformal coverage of the RTE SnOx thin film and the perovskite layer on a textured Si surface was achieved, which is helpful for making fully textured monolithic perovskite/silicon tandem solar cells in the future.

Surface passivation and optical design of silicon heterojunction solar cells

In this paper, the wx-AMPS simulation software is used to model and simulate the antimony selenide (Sb<sub>2</sub>Se<sub>3</sub>) thin film solar cells. Three different electron transport layer models (CdS, ZnO and SnO<sub>2</sub>) are applied to the Sb<sub>2</sub>Se<sub>3</sub> solar cells, and the conversion efficiencies of which are obtained to be 7.35%, 7.48% and 6.62% respectively. It can be seen that the application of CdS and ZnO can achieve a better device performance. Then, the electric affinity of the electron transport layer (<i>χ</i><sub>e-ETL</sub>) is adjusted from 3.8 eV to 4.8 eV to study the effect of the energy band structure change on the solar cell performance. The results show that the conversion efficiency of the Sb<sub>2</sub>Se<sub>3</sub> solar cell first increases and then decreases with the increase of the <i>χ</i><sub>e-ETL</sub>. The lower <i>χ</i><sub>e-ETL</sub> creates a barrier at the interface between the electron transport layer and the Sb<sub>2</sub>Se<sub>3</sub> layer, which can be considered as a high resistance layer, resulting in the increase of series resistance. On the other hand, when the <i>χ</i><sub>e-ETL</sub> is higher than 4.6 eV, the electric field of the electron transport layer can be reversed, leading to the accumulation of the photon-generated carriers at the interface between the transparent conductive film and the electron transport layer, which could also hinder the carrier transport and increase the series resistance. At the same time, the electric field of Sb<sub>2</sub>Se<sub>3</sub> layer becomes weak with the value of <i>χ</i><sub>e-ETL</sub> increasing according to the band structure of the Sb<sub>2</sub>Se<sub>3</sub> solar cell, leading to the increase of the carriers' recombination and the reduction of the cell parallel resistance. As a result, too high or too low <i>χ</i><sub>e-ETL</sub> can lower the FF value and cause the device performance to degrade. Thus, to maintain high device performance, from 4.0 eV to 4.4 eV is a suitable range for the <i>χ</i><sub>e-ETL</sub> of the Sb<sub>2</sub>Se<sub>3</sub> solar cell. Moreover, based on the optimization of the <i>χ</i><sub>e-ETL</sub>, the enhancement of the Sb<sub>2</sub>Se<sub>3</sub> layer material quality can further improve the solar cell performance. In the case of removing the defect states of the Sb<sub>2</sub>Se<sub>3</sub> layer, the conversion efficiency of the Sb<sub>2</sub>Se<sub>3</sub> solar cell with a thickness of 0.6 μm is significantly increased from 7.87% to 12.15%. Further increasing the thickness of the solar cell to 3 μm, the conversion efficiency can be as high as 16.55% (<i>J</i><sub>sc</sub>=34.88 mA/cm<sup>2</sup>, <i>V</i><sub>oc</sub>=0.59 V, <i>FF</i>=80.40%). The simulation results show that the Sb<sub>2</sub>Se<sub>3</sub> thin film solar cells can obtain excellent performance with simple device structure and have many potential applications.

Design perspectives of a thin film GaAs solar cell integrated with Carrier Selective contacts and anti-reflection coatings: Optical and device analysis

Zinc oxide (ZnO), an attractive functional material having fascinating properties like large band gap (~3.37 eV), large exciton binding energy (~60 meV), high transparency, high thermal, mechanical and chemical stability, easy tailoring of structural, optical and electrical properties, has drawn a lot of attention for its optoelectronic applications including energy harvesting. Some of the promising applications are solar cells, ultraviolet light emitting diodes, photodiodes, ultraviolet lasers, high-temperature electronics, and spintronics devices. ZnO is a very versatile material vindicating itself with different access such as nanostructures, epitaxial structures, composite, and thin films. The ZnO nanostructures exist in various shapes and sizes including 0-D (nanoparticles), 1-D (nanowires, nanorods), 2-D (nanopetals, sheets), and 3-D (nanoflowers, tetrapods) structures with its tunable band gap energy, nature malleable behavior, and its potential application in optoelectronic devices. The ZnO being naturally an n-type inorganic semiconductor has been used in various types of solar cells such as conventional Si wafer solar cells, thin film solar cells, organic solar cells (OPVs), dye-sensitized solar cells (DSSCs), perovskite solar cells, hybrid solar cells (HSCs), and in several organic/inorganic as well as inorganic/inorganic heterojunction solar cell concepts. The ZnO acts as electron transport material, thereby it plays a major role in all the emerging third-generation PV devices. The ZnO thin films have manifold properties to make it interesting in photovoltaic applications. The ZnO thin film, owing to its easy synthesis and simple deposition techniques, reliability, cost effectiveness, non-toxicity, high stability, and good optoelectronic properties, has been studied extensively in several PV devices including the conventional silicon wafer-based solar cells as an antireflection and surface passivation layer. Here, a short review on ZnO nanostructures and thin films is presented in the perspective of their photovoltaic applications in different roles which include, as capping layer, electron selective layer, window layer, buffer layer, antireflection and passivation layer, as well as active layer for different types of solar cells. A brief overview of the synthesis methods of ZnO nanostructures and different deposition techniques of ZnO thin films via physical methods, cost-effective chemical routes and green methods is discussed. A brief discussion on the structural, optical, and electrical properties of the ZnO nanostructures and thin films is also included which are important for their PV applications. Finally, the chapter briefly outlines the different types of solar cells’ structures employing ZnO (nanostructures and thin films) in different roles, progress so far, their state-of-art-performance, and the challenges associated with different ZnO-based photovoltaic devices are critically discussed. At last, chapter closes with a summary including a remark indicating the future prospects of ZnO-based PV devices.

Recent breakthroughs in solar cell technology have highlighted transition metal dichalcogenides, particularly tungsten diselenide (WSe₂), as exceptional absorber materials due to their remarkable optoelectronic properties. This study presents an innovative thin-film photovoltaic solar cell featuring Cu₂O-WSe₂-SnS₂ layers. Utilizing WSe₂ as the primary absorber, SnS₂ as the electron transport layer (ETL), and Cu₂O as the hole transport layer (HTL), this structure is engineered to maximize light absorption and carrier separation, enhancing energy efficiency. Key performance parameters, including power conversion efficiency (PCE), fill factor (FF), short-circuit current density (Jsc), and open-circuit voltage (Voc), were thoroughly evaluated. The impressive results—PCE of 25.76%, FF of 83.36%, Voc of 1.29 V, and Jsc of 23.84 mA/cm²—were achieved through meticulous simulation and experimental validation. Investigating defect densities at the SnS₂/WSe₂ and WSe₂/Cu₂O interfaces revealed that minimizing interfacial recombination significantly enhances charge extraction and overall performance. A comparative analysis confirmed SnS₂ as an optimal ETL due to superior electron mobility and minimal recombination. This optimized structure offers excellent efficiency and operational stability, providing crucial insights into the feasibility of WSe₂-based thin-film solar cells. Additionally, it advances our understanding of interfacial engineering in photovoltaics and underscores the role of WSe₂ in conjunction with Cu₂O and SnS₂. These findings contribute to ongoing research on high-efficiency thin-film solar cells, paving the way for further innovations in solar energy conversion technology.

Investigations on the effect of buffer layer on CMTS based thin film solar cell using SCAPS 1-D

In this research, a numerical simulation and analysis of the second generation thin film solar cell Copper Indium Gallium diselenide, Cu(In,Ga)Se2 or, CIGS, is conducted in order to optimize its performance and compare among the cells using different materials for buffer and window layers. The one-dimensional solar cell simulation program SCAPS-1D (Solar Cell Capacitance Simulator) is used for the simulation and analysis purpose. The effects of variation of bandgap, concentration and thickness of the p-type CIGS absorber layer on the efficiency of CIGS solar cell are investigated. The change in CIGS solar cell efficiency with change in temperature is studied, too. Two different buffer layers namely CdS and In2S3 are considered for the simulation of the CIGS solar cell. The thickness of the buffer layer, its bandgap and concentration are taken into consideration for optimization. As for the window layer, ZnO and SnO2 are employed for the numerical simulation. The thickness of the window layer is varied and its effect on the efficiency of the solar cell is investigated. The open-circuit voltage, short-circuit current density, fill factor and quantum efficiency of the CIGS solar cell are observed from the SCAPS simulation besides the solar cell efficiency. A comparison among the different CIGS cell structures employing different buffer layers and window layers is performed in terms of efficiency and other essential parameters as mentioned above. The solar cell performances of the structures explored in this work were also put in comparison against some laboratory research cell output. The simulation result shows a possible better performance for all the simulated CIGS cell structures compared to the experimental results. In2S3 appears to increase efficiency and thus poses a great potential for non-toxic CIGS solar cell. Though CIGS absorber layer requires more thickness for desired output, successful application of much thinner SnO2 replacing ZnO buffer layer paves the way to less thicker CIGS thin film solar cell.

In this research work, a copper bismuth oxide- (CuBi2O4-) based thin-film solar cell has been proposed for the lead and toxic-free (Al/ITO/TiO2/CuBi2O4/Mo) structure simulated in SCAPS-1D software. The main aim of this work to make an ecofriendly and highly efficient thin-film solar cell. The absorber layer CuBi2O4, buffer layer TiO2, and the electron transport layer (ETL) ITO have been used in this simulation. The performance of the suggested photovoltaic devices was quantitatively evaluated using variations in thickness such as absorber, buffer, defect density, operating temperature, back contact work function, series, shunt resistances, acceptor density, and donor density. The absorber layer thickness is fixed at 2.0 μm, the buffer layer at 0.05 μm, and the electron transport layer at 0.23 μm, respectively. The CuBi2O4 absorber layer produces a solar cell efficiency of 31.21%, an open-circuit voltage ( V oc ) of 1.36 V, short-circuit current density ( J sc ) of 25.81 mA/cm2, and a fill factor (FF) of 88.77%, respectively. It is recommended that the proposed CuBi2O4-based structure can be used as a potential for thin-film solar cells that are both inexpensive and highly efficient.

In this work, a titanium oxide buffer layer was explored as a possible buffer electron transporting layer (ETL) with iodine-tin-based perovskite material for enhancement of a thin-film lead-free perovskite solar cell. The open-circuit voltage of the device was used as an indicator for the interface energy barrier’s change with the thickness of the TiO2. The buffer and photoabsorbing layers were deposited by vacuum reactive sputtering and a low-temperature ion-assisted process from a confocal sintered source, respectively, allowing precise tuning of the film properties and reproducibility of the solar cell behavior. The surface roughness of the buffer layers was investigated by atomic force microscopy and together with the measured absorbance spectra conclusions about the optical losses in the device were made. It was found that the highest voltage was generated from the structure with 75 nm-thick ETL. The electrical behavior of the cell with this buffer layer was additionally studied by impedance measurements. Small interface capacitance and contact resistance were obtained and considered suitable for photodetector fabrication. The practical applicability of the structure with a dual function of self-powered photodetection was demonstrated by the measurement of the response time.

Light management in thin-film silicon solar cells