Numerical Simulation and Optimization of Highly Stable and Efficient Lead-Free Perovskite FA(1-x)Cs(x)SnI(3)-Based Solar Cells Using SCAPS

SCAPS-1D Modeling of Hydrogenated Lead-Free Cs2AgBiBr6 Double Perovskite Solar Cells with a Remarkable Efficiency of 26.3

In this investigation, we employ a numerical simulation approach to model a hydrogenated lead-free Cs2AgBiBr6 double perovskite solar cell with a p-i-n inverted structure, utilizing SCAPS-1D. Contrary to traditional lead-based perovskite solar cells, the Cs2AgBiBr6 double perovskite exhibits reduced toxicity and enhanced stability, boasting a maximum power conversion efficiency of 6.37%. Given its potential for improved environmental compatibility, achieving higher efficiency is imperative for its practical implementation in solar cells. This paper offers a comprehensive quantitative analysis of the hydrogenated lead-free Cs2AgBiBr6 double perovskite solar cell, aiming to optimize its structural parameters. Our exploration involves an in-depth investigation of various electron transport layer materials to augment efficiency. Variables that affect the photovoltaic efficiency of the perovskite solar cell are closely examined, including the absorber layer's thickness and doping concentration, the hole transport layer, and the absorber defect density. We also investigate the impact of the doping concentration of the electron transport layer and the energy level alignment between the absorber and the interface on the photovoltaic output of the cell. After careful consideration, zinc oxide is chosen to serve as the electron transport layer. This optimized configuration surpasses the original structure by over four times, resulting in an impressive power conversion efficiency of 26.3%, an open-circuit voltage of 1.278 V, a fill factor of 88.21%, and a short-circuit current density of 23.30 mA.cm-2. This study highlights the critical role that numerical simulations play in improving the chances of commercializing Cs2AgBiBr6 double perovskite solar cells through increased structural optimization and efficiency.

Device Simulation of Highly Stable and 29% Efficient FA0.75MA0.25Sn0.95Ge0.05I3-Based Perovskite Solar Cell

A new type of perovskite solar cell based on mixed tin and germanium has the potential to achieve good power conversion efficiency and extreme air stability. However, improving its efficiency is crucial for practical application in solar cells. This paper presents a quantitative analysis of lead-free FA_0.75MA_0.25Sn_0.95Ge_0.05I₃ using a solar cell capacitance simulator to optimize its structure. Various electron transport layer materials were thoroughly investigated to enhance efficiency. The study considered the impact of energy level alignment between the absorber and electron transport layer interface, thickness and doping concentration of the electron transport layer, thickness and defect density of the absorber, and the rear metal work function. The optimized structures included poly (3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT:PSS) as the hole transport layer and either zinc oxide (ZnO) or zinc magnesium oxide (Zn_0.7Mg_0.3O) as the electron transport layer. The power conversion efficiency obtained was 29%, which was over three times higher than the initial structure. Performing numerical simulations on FA_0.75MA_0.25Sn_0.95Ge_0.05I₃ can significantly enhance the likelihood of its commercialization. The optimized values resulting from the conducted parametric study are as follows: a short-circuit current density of 30.13 mA·cm^-2), an open-circuit voltage of 1.08 V, a fill factor of 86.56%, and a power conversion efficiency of 28.31% for the intended solar cell.

Lead-Free FACsSnI3 Based Perovskite Solar Cell: Designing Hole and Electron Transport Layer

In recent years, lead-based perovskites solar cells have demonstrated excellent power-conversion efficiency. Despite their remarkable progress, the commercialization of lead-based perovskites is hampered by lead toxicity concerns. The recently discovered non-toxic FACsSnI₃ perovskite has the potential to replace lead-based perovskites in solar cell applications. Since the perovskite material FACsSnI₃ (FA_0.85Cs_0.15SnI₃) is relatively new, there is a lack of information, particularly regarding the design features required for electron and hole-transport layers for efficient photovoltaic responses. The important variables, such as electron affinity, energy band gap, film thickness, and doping density of both electron and hole-transport layers, were simulated and modeled separately and iteratively in this study to achieve the most efficient photovoltaic response. Finally, the absorber layer thickness of FACsSnI₃ perovskite is tuned to achieve a maximum power-conversion efficiency of slightly more than 24%. We hope that the findings of this study will serve as a strong guideline for future research and the design of lead-free perovskite solar cells for efficient photovoltaic responses.

Nitrogen-Doped Titanium Dioxide as a Hole Transport Layer for High-Efficiency Formamidinium Perovskite Solar Cells

Perovskite solar cells (PSCs) offer advantages over widely deployed silicon solar cells in terms of ease of fabrication; however, the device is still under rigorous materials optimization for cell performance, stability, and cost. In this work, we explore a version of a PSC by replacing the polymeric hole transport layer (HTL) such as Spiro-OMeTAD, P3HT, and PEDOT: PSS with a more air-stable metal oxide, viz., nitrogen-doped titanium dioxide (TiO₂:N). Numerical simulations on formamidinium (FA)-based PSCs in the FTO/TiO₂/FAPbI₃/Ag configuration have been carried out to depict the behaviour of the HTL as well as the effect of absorber layer thickness (∆t) on photovoltaic parameters. The results show that the cell output increases when the HTL bandgap increases from 2.5 to 3.0 eV. By optimizing the absorber layer thickness and the gradient in defect density (Nt), the device structure considered here can deliver a maximum power conversion efficiency of ~21.38% for a lower HTL bandgap (~2.5 eV) and ~26.99% for a higher HTL bandgap of ~3.0 eV. The results are validated by reproducing the performance of PSCs employing commonly used polymeric HTLs, viz. Spiro-OMeTAD, P3HT, and PEDOT: PSS as well as high power conversion efficiency in the highly crystalline perovskite layer. Therefore, the present study provides high-performing, cost-effective PSCs using TiO₂:N.

Simulation and Investigation of 26% Efficient and Robust Inverted Planar Perovskite Solar Cells Based on GA0.2FA0.78SnI3-1%EDAI2 Films

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)/GA0.2FA0.78SnI3-1% EDAI2 (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 GA0.2FA0.78SnI3-1% EDAI2 could greatly increase its chance for commercial development.