In this investigation, we employ a numerical simulation approach to model a hydrogenated lead-free ${\mathrm{C}\mathrm{s}}_2\mathrm{A}\mathrm{g}\mathrm{B}\mathrm{i}{\mathrm{B}\mathrm{r}}_6$ double perovskite solar cell with a p-i-n inverted structure, utilizing SCAPS-1D. Contrary to traditional lead-based perovskite solar cells, the ${\mathrm{C}\mathrm{s}}_2\mathrm{A}\mathrm{g}\mathrm{B}\mathrm{i}{\mathrm{B}\mathrm{r}}_6$ double perovskite exhibits reduced toxicity and enhanced stability, boasting a maximum power conversion efficiency of $\mathrm{6.37\%}$. 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 ${\mathrm{C}\mathrm{s}}_2\mathrm{A}\mathrm{g}\mathrm{B}\mathrm{i}{\mathrm{B}\mathrm{r}}_6$ 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 $\mathrm{26.3\%}$, an open-circuit voltage of $1.278 \mathrm{V}$, a fill factor of $\mathrm{88.21\%}$, and a short-circuit current density of $23.30 \mathrm{m}\mathrm{A}.{\mathrm{c}\mathrm{m}}^{-2}$. 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.

Formamidinium tin iodide (FASnI₃)-based perovskite solar cells (PSCs) have achieved significant progress in the past several years. However, these devices still suffer from low power conversion efficiency ($\mathrm{PCE}=6\%$) and poor stability. Recently, Cesium (Cs)-doped Formamidinium tin iodide (${\mathrm{FA}}_{1-\mathrm{x}}{\mathrm{Cs}}_{\mathrm{x}}{\mathrm{SnI}}_3)$ showed enhanced air, thermal, and illumination stability of PSCs. Hence, in this work, ${\mathrm{FA}}_{1-\mathrm{x}}{\mathrm{Cs}}_{\mathrm{x}}{\mathrm{SnI}}_3$ PSCs have been rigorously studied and compared to pure FASnI₃ PSCs using a solar cell capacitance simulator (SCAPS) for the first time. The aim was to replace the conventional electron transport layer (ETL) TiO₂ that reduces PSC stability under solar irradiation. Therefore, ${\mathrm{FA}}_{1-\mathrm{x}}{\mathrm{Cs}}_{\mathrm{x}}{\mathrm{SnI}}_3$ PSCs with different Cs contents were analyzed with TiO₂ and stable ZnOS as the ETLs. Perovskite light absorber parameters including Cs content, defect density, doping concentration and thickness, and the defect density at the interface were tuned to optimize the photovoltaic performance of the PSCs. The simulation results showed that the device efficiency was strongly governed by the ETL material, Cs content in the perovskite and its defect density. All the simulated devices with ZnOS ETL exhibited $\mathrm{PCEs}$ exceeding $20\%$ when the defect density of the absorber layer was below ${10}^{15}{ \mathrm{cm}}^{-3}$, and deteriorated drastically at higher values. The optimized structure with ${\mathrm{FA}}_{75}{\mathrm{Cs}}_{25}{\mathrm{SnI}}_3$ as light absorber and ZnOS as ETL showed the highest $\mathrm{PCE}$ of $22\%$ with an open circuit voltage ${\mathrm{V}}_{\mathrm{oc}}$ of $0.89 \mathrm{V}$, short-circuit current density ${\mathrm{J}}_{\mathrm{sc}}$ of $31.4 \mathrm{mA}·{\mathrm{cm}}^{-2}$, and fill factor FF of $78.7\%$. Our results obtained from the first numerical simulation on Cs-doped FASnI₃ could greatly increase its potential for practical production.

Three different samples were synthesized based on polyepoxide resin, a solidifying agent, and a Bi₂O₃ doping compound. The polyepoxide resin and solidifying agent were added in a 2:1 ratio by weight and the Bi₂O₃ compound was added in ratios of 0, 5, and 10 wt. %. The density of the synthesized composites was measured using an MH-300A densimeter with an uncertainty in measurement of 0.001 g/cm³. The measurements showed that the density of the fabricated composite varied from 1.103 g/cm³ to 1.20 g/cm³ when the reinforcing Bi₂O₃ compound was raised from 0 wt. % to 10 wt. %. Furthermore, the γ-ray shielding parameters were evaluated based on the simulated mean track length of γ-photons inside the synthesized composites using MCNP-5 code. The simulated results show an enhancement in the shielding parameter when increasing the Bi₂O₃ concentration, where the linear attenuation coefficient values increased from 0.101 cm⁻¹ to 0.118 cm⁻¹ as the Bi₂O₃ concentration increased from 0 to 10 wt. %. The increase in the LAC has a positive effect on the other shielding properties.

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.

A hybrid tin-based (GA${}_{0.2}$FA${}_{0.78}$SnI${}_3$-1% EDAI${}_2$) perovskite solar cell (PSC) with a p-i-n inverted structure has been reported to pass all the rigorous standard tests successfully and achieve a certified power conversion efficiency (PCE) of 8.3%. Our previous numerical study showed that this PCE could be considerably increased to 24.1% by engineering and controlling the interfaces of the cell. The aim of the current study is to compare the performance of a conventional n-i-p structure with its inverted p-i-n analog quantitatively, and demonstrate that, by improving the conventional structure, it can achieve a PCE score approximately equal to the inverted p-i-n structure. To that end, the absorber layer was chosen to be GA${}_{0.2}$FA${}_{0.78}$SnI${}_3$-1% EDAI${}_2$, while four ETL (electron transport layer) materials (TiO${}_2$, WS${}_2$, SnO${}_2$, and ZnOS), and four HTL (hole transport layer) materials (PEDOT:PSS, Cu${}_2$O, CuSCN, and CuI) were considered. Most used ETL/HTL combinations have been rigorously investigated with the aim of finding the ultimate configuration, providing the highest photovoltaic properties. Additionally, the effect of the layers’ thicknesses and their doping concentrations were inspected, and their impact on the photovoltaic properties of the PSC was investigated. The optimized structure with CuI (copper iodide) as the HTL and ZnOS (zinc oxysulphide) as the ETL scored a PCE of 24.1%, which is comparable to the value found with the inverted structure (26%). The current numerical simulation on GA${}_{0.2}$FA${}_{0.78}$SnI${}_3$-1% EDAI${}_2$ could be considered as a milestone in its chances for commercial development.

This study explores the application of machine learning techniques, specifically principal component analysis (PCA), to analyze the influence of silica content on the physical and chemical properties of aerogels. Silica aerogels are renowned for their exceptional properties, including high porosity, large surface area, and low thermal conductivity, but their mechanical brittleness poses significant challenges. The study initially utilized cross-correlation analysis to examine the relationships between key properties such as the Brunauer–Emmett–Teller (BET) surface area, pore volume, density, and thermal conductivity. However, weak correlations prompted the application of PCA to uncover deeper insights into the data. The PCA results demonstrated that silica content has a significant impact on aerogel properties, with the first principal component (PC1) showing a strong positive correlation (R² = 94%) with silica content. This suggests that higher silica levels correspond to lower thermal conductivity, porosity, and BET surface area, while increasing the density and elastic modulus. Additionally, the analysis identified the critical role of thermal conductivity in the second principal component (PC2), particularly in samples with moderate to high silica content. Overall, this study highlights the effectiveness of machine learning techniques like PCA in optimizing and understanding the complex inter-relationships among the physico-chemical properties of silica aerogels.