Solar Cell Structure Research Articles

Synthesis, Characterization, and Electrical Properties of CdO-Doped Polyaniline for Enhanced Hole Extraction and Performance in Inverted Perovskite Solar Cells

Abstract PEDOT: PSS is recognized as one of the most conductive polymers used as an organic hole transport layer (HTL) in inverted perovskite solar cell (PSC) structures. However, its acidic nature and valence band mismatch with the adjacent perovskite layer often led to reduced efficiency and lower open-circuit voltage (VOC) in PSCs. To address these limitations, we incorporated polyaniline (PANI) doped with varying amounts of CdO (x = 0, 1, 5, and 10%), referred to as PANI-CdO (x%). The synthesized CdO samples were thoroughly characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Electrical measurements demonstrated that the addition of CdO enhanced the conductivity and mobility of PANI, contributing to the improved performance of the PSCs. Specifically, the device incorporating the CdO (5%)-doped PANI exhibited superior power conversion efficiency (PCE) of 14.71%, compared to 13.38% for the pristine PEDOT: PSS device. Additionally, VOC increased from 1.02 V (pristine PEDOT: PSS) to 1.11 V (CdO 5% doped PANI), reflecting better energy band alignment and reduced recombination losses. Furthermore, the short-circuit current density (JSC) also improved from 17.01 mA/cm2 to 17.67 mA/cm2, indicating enhanced charge extraction and transport efficiency. Graphical Abstract

Theoretical Analysis of Power Conversion Efficiency of Lead-Free Double-Perovskite Cs2TiBr6 Solar Cells with Different Hole Transport Layers

In recent years, there has been significant investigation into the high efficiency of perovskite solar cells. These cells have the capacity to attain efficiencies above 14%. As the perovskite materials that include lead pose a substantial environmental risk, components that are free from lead are used during the process of solar cell development. In this work, we use a lead-free double-perovskite material, namely Cs2TiBr6, as the main absorbing layer in perovskite solar cells to enhance power conversion efficiency (PCE). This work is centered on the development of solar cell structures with materials such as an ETL (electron transport layer) and an HTL (hole transport layer) to enhance the PCE. In this theoretical work, we perform simulations and analysis on double-perovskite Cs2TiBr6 to assess its efficacy as an absorber material in various HTLs like Cu2O and CuI, with a fixed ETL of C60 using SCAPS (Solar Cell Capacitance Simulator, SCAPS 3.3.10) Software. This is a one-dimensional solar cell simulation program. In this work, the thickness of the double-perovskite material is also varied between 0.2 and 2.0 µm, and its efficiency is observed. The effect of temperature variation on efficiency in the range of 300 K to 350 K is observed. The effect of defect density on efficiency is also observed in the range of 1 × 1011 to 1 × 1016. In this theoretical work, perovskite solar cells, including their absorbing layer, demonstrate outstanding ETLs and HTLs, respectively. As a result, the cells’ achieved PCE is improved. This work demonstrates the effectiveness of this lead-free double-perovskite structure that absorbs light in perovskite solar cells.

Rethinking CIGS solar cells for rear illumination applications

Abstract This study introduces a chalcogenide-based thin-film solar cell structure optimized for rear illumination, featuring a thinner, wide-bandgap Cu(In,Ga)S2 chalcopyrite absorber. Matching the performance of traditional front-illuminated designs, this configuration paves the way for further photoelectrochemical advances thanks to its metallic top layer, which can serve as a versatile grafting platform that is resistant to their operating conditions.

Design and Synthesis of Crystalline Al-Doped TiO2 Buffer Layers for Enhancing Energy Conversion Efficiency of New Photovoltaic Devices

Perovskite solar cells (PSCs) characterized by high energy conversion efficiency (ECE) and low manufacturing costs, exhibit promising potential for commercialization in the near term. For commercialization, it is very important to prevent the decomposition of perovskite by ultraviolet (UV) radiation in the air environment. Also, the mesoscopic architecture of PSCs presents considerable opportunities for the solar cell industry, offering potential for recycling of spent photocatalytic materials such as TiO2, and exploration of new energy resources. To solve these problems, therefore, this study introduces a strategy to mitigate these challenges using a crystalline Al-doped TiO2 buffer layer as the electron transport layer (ETL) in conjunction with a mesoporous TiO2 layer in the fabrication of PSCs. Among various Al concentrations in the crystalline Al-doped TiO2 buffer layer fabricated via spin-coating, an optimum concentration of 7 mol% Al yielded the highest cell performance in the specific perovskite solar cell structure. These solar cells exhibited an impressive ECE of 11.87%, representing a substantial enhancement of nearly double the ECE (6.37%) achieved with the conventional ETL. This remarkable improvement can be attributed to the passivation effect of the newly developed ETL, which combines a crystalline Al-doped TiO2 buffer layer with a mesoporousTiO2 layer. Electrochemical impedance spectroscopy (EIS) analysis was performed in conjunction with theoretical calculations of charge transport parameters to substantiate this claim.

A metasurface light-trapping structure for solar cell applications.

Light trapping structures can enhance the absorption and reduce the thickness and costs of solar cells. Among light trapping structures, the metasurface structure utilizes Mie scattering to make light enter the solar active layer better, thus improving the photovoltaic conversion efficiency of solar cells. Herein, we simulated and optimized a metasurface light-trapping structure for solar cells and implemented this structure on solar cells. Simulation results of thin-film silicon-based solar cells show that the maximum short-circuit current can be increased to 24.46 mA/cm2 using a metasurface light-trapping structure, which is an increase of 40.49% compared to the reference bare cell. In addition, when this metasurface structure is integrated into a crystalline silicon solar cell, we find that the maximum short-circuits current reaches 29.09 mA/cm2, which is an even more significant improvement of 54.6% compared to the reference bare cell, and the power conversion efficiency increases by 7.14%. This study verifies the effect of a metasurface light-trapping structure on the light absorption of silicon-based solar cells.

Progress in crystalline silicon heterojunction solar cells

Key materials and device structures of crystalline silicon heterojunction solar cells.

Homotypic Heterojunction of Metal Oxygen/Sulfide as an Electron Transport Layer for High-Performance Perovskite Solar Cells

The electron transport layer (ETL), as a critical component of a perovskite solar cell structure, establishes an electron-selective contact with the perovskite absorber layer. In this work, the synthesized SnS2...

Unlocking the full potential of solar cell materials: parameter sensitivity analysis and optimization using response surface modelling

This study introduces response surface modelling for predicting solar cell efficiency and conducting sensitivity analysis of key parameters and their interactions and optimizing interacting solar cell structure parameters for the best performance.

Photoelectric characteristic of hybrid thin-film solar cells and metasurface absorbers

Abstract As the demand for high-efficiency, low-cost solar cells continue to increase, existing thin-film solar cells still face many challenges in terms of light absorption efficiency and charge transport performance. To address these issues, we design and study a PEDOT:PSS/CdTe hybrid thin-film solar cell structure combined with a metasurface absorber layer. We use a metasurface structure with a tetragonal embedded ring resonator pattern in the CdTe absorber layer. This structure can produce a strong electric and magnetic field localization effect on the surface of the absorption layer, improving the light absorption rate of the battery. At the same time, the introduction of organic polymer materials (PEDOT: PSS) optimizes the electrode interface quality and reduces the interface defects and composite losses between materials, and further improves the photoelectric conversion efficiency (PCE) of the battery. we introduce traditional absorption enhancement methods (titanium nanoparticle arrays and pyramid TiO2 arrays) to this structure. The solar cell proposed has a spectral response rate of 96.71% and its PCE reaches 35.66%. The research indicates that the new structure holds significant potential for the application of high-efficiency solar cells, offering new ideas for the design and manufacture of solar cells in the future.

Photovoltaic Effect and Efficiency of Perovskite Solar Cells

Recently, the solar cells have become a hotspot as the solar power is becoming more and more popular. There are many types of solar cells. Perovskite solar cells (PSCs), as a type of solar cell, use perovskite type semiconductors as the light absorbing materials. PSCs exhibit high efficiency and stability. The performance of solar cells could be evaluated by the photovoltaic effect. Therefore, the research on the photovoltaic effect of perovskite solar cells is of importance. This essay gives a brief introduction to the composition and structure of perovskite solar cells. Then, it introduces the photovoltaic effect of perovskite solar cells in two parts which include working principle and efficiency of PSCs. In order to further elucidate the mechanism of PSCs, the influencing factors of photovoltaic effect are discussed. Meanwhile, the limitations and challenges of perovskite solar cells are outlined. Besides, the future development trend regarding these issues is outlined. This work will help to promote further development of this field.

Modification on electrical characteristics of interface states by using nitrogen and phosphorus co-doped polysilicon in tunnel oxide passivation contact silicon solar cells

The influence on electrical characteristics of interface states by using nitrogen (N) and phosphorus (P) co-doped polysilicon (poly-Si) in tunnel oxide passivation contact silicon solar cells has been investigated. We find that the introduction of N co-doping in P heavily doped poly-Si decreases its own work function; thus, the built-in potential of the poly-Si (n+)/tunnel SiOx/c-Si (p) junction is notably enhanced. The electrical characteristics of interface states at tunnel SiOx/c-Si in the junction have been investigated by current/capacitance–voltage deconvolution. The measured results suggest that the interface state density is reduced, and the corresponding capture cross section ratio σe/σh is increased by three orders of magnitude in the junction with N co-doped poly-Si. The obtained results not only reveal the underlying mechanism of the enhanced contact passivation effect by introducing N co-doped poly-Si but also give an enlightening idea for the design of passivation contact structure in crystalline silicon solar cells.

Efficiency enhancement of WSe2/In2S3 solar cell by numerical modeling using SCAPS

Tungsten diselenide (WSe2), a transition metal dichalcogenide (TMDC) compound, is considered a promising material for application in thin film solar cells because of its high carrier transport, tunable band gap, and high absorption coefficient. In this work, solar cell structure comprising FTO/In2S3/WSe2 is modeled using one-dimensional solar cell capacitance simulator (SCAPS-1D) software where wide bandgap widely accessible In2S3 is used as a novel buffer layer instead of toxic CdS buffer layer for WSe2-based solar cell. The effect of thickness, doping concentrations, defect density, radiative recombination coefficient, and the electron and hole capture cross-section are analyzed and optimized. After optimizing the device, the effect of operating temperature, shunt and series resistance and back contact work function are also investigated. At an optimized WSe2 absorber layer thickness of 1.5 µm and acceptor density of 1017 cm−3, efficiency of 22.53%, fill factor of 84.98%, open circuit voltage of 1.096 V, and short circuit current density of 24.18 mA/cm2 was obtained. Additionally, a back surface field (BSF) layer comprising amorphous silicon (a-Si) of thickness 0.05 µm is introduced between the absorber layer and the back contact to lessen carrier recombination at the back surface. Therefore, the efficiency rises from 22.53% to 29.5% with a fill factor of 89.53%, open circuit voltage of 1.26 V, and short circuit current density of 26.23 mA/cm2. The simulation results suggest that WSe2-based thin-film solar cells can be designed and fabricated with high efficiency and cost advantage.

Progress in the Stability of Small Molecule Acceptor-Based Organic Solar Cells.

Significant advancements in power conversion efficiency have been achieved in organic solar cells with small molecule acceptors. However, stability remains a primary challenge, impeding their widespread adoption in renewable energy applications. This review summarizes the degradation of different layers within the device structure in organic solar cells under varying conditions, including light, heat, moisture, and oxygen. For the photoactive layers, the chemical degradation pathways of polymer donors and small molecule acceptors are examined in detail, alongside the morphological stability of the bulk heterojunction structure, which plays a crucial role in device performance. The degradation mechanisms of commonly used anode and cathode interlayers and electrodes are addressed, as these layers significantly influence overall device efficiency and stability. Mitigation methods for the identified degradation mechanisms are provided in each section to offer practical insights for improving device longevity. Finally, an outlook presents the remaining challenges in achieving long-term stability, emphasizing research directions that require further investigation to enhance the reliability and performance of organic solar cells in real-world applications.

Numerical optimization of all-inorganic CsSnBr3 perovskite solar cells: the observation of 27% power conversion efficiency

Abstract In this research, we employed SCAPS-1D simulation software to numerically optimize the performance of four CsSnBr3-based perovskite solar cell structures. Specifically, we analyzed the FTO/ZnO/CsSnBr3/rGO/Se, FTO/AlZnO/CsSnBr3/rGO/Se, FTO/LiTiO2/CsSnBr3/rGO/Se, and FTO/WS2/CsSnBr3/rGO/Se configurations. The optimization process focused on adjusting the thicknesses of the electron transport layer, hole transport layer, and perovskite layer, while also evaluating the effects of temperature, series resistance, and shunt resistance on the Jsc, Voc, FF, and PCE. As a result, we achieved PCE of 26.92%, 26.89%, 26.89%, and 26.91% for the FTO/AlZnO, FTO/ZnO, FTO/LiTiO2, and FTO/WS2-based structures, respectively. Furthermore, the PCE obtained for all CsSnBr3-based perovskite solar cell structures outperformed the recently reported ITO/WS2/CsSnBr3/Cu2O/Au perovskite solar cell, which exhibited the highest PCE in the literature, by nearly 5%.

Highly passivating and blister-free electron selective Poly-Si based contact fabricated by PECVD for crystalline silicon solar cells

We optimized a fabrication process to attain blister-free n-type tunnel oxide passivated contact structures while ensuring high-quality passivation properties. To suppress blister formation, we introduced an intrinsic inner layer between the tunnel silicon oxide layer and the amorphous silicon layer. The intrinsic inner layer was a micro-crystalline silicon or poly-crystalline silicon. The poly-crystalline silicon layer was formed by annealing step after amorphous silicon and HF treatment. Consequently, the addition of elements such as carbon or nitrogen to the doped amorphous silicon was not necessary, effectively preventing blistering. A symmetrical sample fabricated using a poly-crystalline silicon inner layer formed by annealing amorphous silicon, demonstrated high passivation properties, implied open circuit voltage greater than 720 mV. The solar cell tests results showed 21.2 % cell efficiency. The fabrication of the tunnel oxide passivated contact structure using the proposed method successfully highlights its potential to achieve high cell performance in solar cell structures.

Enhancing performance of antimony selenide solar cell with different back surface field configurations

Abstract This study focuses on optimization of solar cells using antimony selenide (Sb2Se3) as absorber layer. A novel solar cell structure, designed and simulated with configuration ZnO/i-ZnO/Sb2Se3/NiO or SnS, demonstrates a notable efficiency improvement. The performance of this solar cell was rigorously evaluated using the SCAPS simulation tool. Key structural parameters were optimized as follows: ZnO at 30 nm, i-ZnO at 20 nm, Sb2Se3 as active layer at 100 nm, and NiO at 20 nm. NiO & SnS, utilized as a back surface field (BSF), effectively minimizes recombination. Various parameters were analyzed, including the band diagram, thickness, bandgap, doping concentration, effect of concentration on electric field, recombination and generation rates, temperature effects, and series and shunt resistance of proposed structure. The proposed model achieved an efficiency of up to 31.4%, highlighting the potential of NiO & SnS as BSF in antimony selenide solar cells. The metal work functions for front and back contacts are 4.4 eV and 5.1 eV respectively. This breakthrough suggests a transformative path toward significantly enhanced solar cell performance, showcasing the latent potential of NiO BSF in optimizing Sb2Se3-based solar cells.

Achieving 31.16 % efficiency in perovskite solar cells via synergistic Dion-Jacobson 2D-3D layer design

Among environmental friendly energy sources solar energy is prominent one that can be harnessed via photovoltaic (PV) cells. The hybrid organic & inorganic perovskite solar cells (PSCs), have shown appealing PV performance. Halide-based perovskites (PVSK) offer several advantages, including low cost, high efficiency, and ease of fabrication. However, there are stability issues with these 3D perovskite materials. The solar device based on 2D PVSK materials are being used more and more in modern applications to address these problems. Ruddlesden-Popper (RP) & Dion-Jacobson (DJ) phases are the two main forms of 2D PVSK. These materials offer significantly greater stability compared to 3D perovskites, making them a promising alternative. In this study, we combine 2D and 3D perovskites to strengthen both reliability as well as efficiency of 3D PSCs. The present work explores the combined effect of DJ 2D-3D PVSK layers on device performance. The DJ 2D material used is PeDAMA4Pb5I16, while the 3D material is the lead-free, stable CsGeI3-xBrx (with x = 1). The optimized solar cell structure developed in this work consists of (Au/Cu2O/PeDAMA4Pb5I16/CsGeI3-xBrx/PCBM/FTO). A thorough analysis was performed on the impact of various ETLs and HTLs, as well as factors such as defect density (Nt), 2D-3D layer thickness, shallow acceptor density (NA), series (RS) and shunt resistances (RSh), and temperature variations. In the present work, PCE has significantly improved, reaching an amazing 31.16 %. Other noteworthy metrics include a JSC 22.55 mA.cm−2, FF 88.47 % and VOC 1.5617 V, all demonstrating exceptional performance. These results demonstrate the effectiveness of our approach in strengthening the efficiency and performance of DJ 2D-3D PSCs, highlighting their potential for future applications.

Design and performance evaluation of eco-friendly Ba(Zr0.95Ti0.05)S3/MASnI3 based perovskite solar cells utilize a variety of hole and electron transport materials

This research is a comprehensive analysis that provides a new model for perovskite solar cells (PSCs). Halide PSCs are the preferred option for solar absorbers in photovoltaic (PV) technology because it has superior optical properties, enhanced efficiency, lightweight nature, and significantly reduced cost. In this study, the simulation of the double-absorber layer organic–inorganic perovskite solar cells (PSC) has been carried out, where Ba(Zr0.95Ti0.05)S3 is used as the upper absorber layer, and MASnI3 is used as the lower absorber layers. It is examined using the solar cell research software SCAPS-1D simulation package. The main object of this research is to test the congenial components for the hole-transporting layers (HTL) and electron-transporting layers (ETL). In addition, this research goal is to ascertain better parameters for active layer thickness, temperature-absorbing defect density, and metal-work functions for the recommended PV cell performance. After optimizing the proposed solar cell structure by changing various components in ETL and HTL, the highest result attained the FTO/SnS2/Ba(Zr0.95Ti0.05)S3/MASnI3/CuO/Au structure, which exhibits an open circuit voltage of Vo = 1.2907 V, fill factor of 86.21 %, short-circuit current of Jsc = 34.7308 mA/cm2, and a maximum power conversion efficiency (PCE) of 38.65 %. The headway is attained by engaging SnS2 as the ETL and CuO as the HTL in the structure. Using the Scaps-1D simulation, we optimized temperature, thickness, defect density, shallow acceptor density, and back contact work functions. It was attained by leaving a thickness of 1 µm for the MASnI3 absorber and 0.01 µm for the Ba(Zr0.95Ti0.05)S3 absorber.

Numerical simulation to optimize the photovoltaic performances of Cu2ZnSnS4 solar cell with Cu2NiSnS4 as hole transport layer

Cu2ZnSnS4 (CZTS) has been taken as an encouraging absorber material for photovoltaic (PV) device applications due to its earth-abundant composition, favorable bandgap, and non-toxicity. However, the recombination losses at both front and back interfaces in the heterojunction CZTS solar cells provide poor efficiency and open-circuit voltage (Voc). In this study, we have designed and investigated heterojunction CZTS-based solar cell employing Cu2NiSnS4 (CNTS) as hole transport layer (HTL) and tungsten disulfide (WS2) as buffer layer. A novel solar cell structure of Ni/CNTS/CZTS/WS2/FTO/Al has been designed numerically by utilizing the one-dimensional solar cell capacitance simulator (SCAPS-1D). At first, we have verified an experimental structure (Mo/CZTS/CdS/ZnO) with conversion efficiency of 8.38 % without HTL numerically with the help of the SCAPS-1D simulator for the validation purposes. A comparison of the PV performances among different HTLs is provided. It is revealed that the addition of HTL at rear side of the CZTS cell minimizes the carrier recombination, thus improving the device outputs. Also, the lower lattice mismatch between the proposed CNTS HTL and CZTS absorber compared to other HTLs further results in better performances. In addition, a ‘spike like’ band orientation at the CZTS/WS2 interface helps to increase PV outputs by reducing the carrier recombination loss. The output of proposed CZTS heterojunction TFSC is further examined by changing different parameters including thickness, doping concentration, bulk and interface defect densities, temperature, cell resistances, and metal work function. In this work, an optimized thickness for CZTS absorber is found to be 1.0 μm for the cost-effective PV device. A maximum efficiency of 30.26 % including Voc of 1.08 V, short-circuit current density (Jsc) of 31.75 mA/cm2, and fill-factor (FF) of 88.04 % is achieved numerically. Therefore, these findings will help to researchers for designing Cd-free, low-cost, environmentally friendly, and highly efficient CZTS heterojunction TFSC.

Analysis on future development of solar cells focusing on materials and devices

In recent times, solar cells have garnered significant attention due to their numerous advantages. These include continuously improving energy conversion efficiency, a simple solution preparation method, flexibility, lightweight design, wearability, suitability for ultra-lightweight space applications, and low-cost material components. Perovskite solar cells have achieved impressive efficiencies of over 25% by using high-quality perovskite films synthesized at low temperatures and by making advancements in compatible interface and electrode materials. Moreover, the stability of cells has become a major focus of research. This paper analyzes the development history, material system, device structure, challenges, and future development direction of perovskite solar cells. The unique photoelectric properties and tunable band gap of materials have made them a hot topic in the field of solar cells. In this paper, the basic characteristics and synthesis methods of perovskite materials are introduced before discussing the device structure, interface engineering, and stability of perovskite solar cells in detail. Finally, it prospects on the future development trend of perovskite solar cells.