Research Tittle: Investigation of the Performance of CsSn0.25Ge075I3 Perovskite Solar Cells by incorporating Cs2CO3 with the SnO2 electron transport layer 

Research Findings:

In this research, the authors have explored the integration of cesium carbonate (Cs2CO3) with tin dioxide (SnO2) as an electron transport layer (ETL) in CsSn0.25Ge075I3 -based perovskite solar cells, aiming to enhance their overall performance. The synthesized CsSn0.25Ge075I3 perovskite films demonstrated excellent crystallinity and uniformity, as confirmed by X-ray diffraction and scanning electron microscopy. The incorporation of Cs2CO3 as an ETL layer was found to significantly impact device performance. Photovoltaic measurements revealed a remarkable power conversion efficiency (PCE) of 28.2%, which is among the highest reported for CsSn0.25Ge0.75I3 perovskite solar cells to date. The key photovoltaic parameters of the optimized devices include a high open-circuit voltage (Voc) of 1.29 V, an impressive short-circuit current density (Jsc) of 27.16 mA/cm², and an excellent form factor (FF) of 81.62%. 

Research Tittle: Enhancing CsSn0.5Ge0.5I3 Perovskite Solar Cell Performance via Cu2O Hole Transport Layer Integration 

Research Findings: 

The primary objective of this research is to investigate the use of Cu2O as a hole transport layer in combination with lead-free metal halide perovskite (CsSn0.5­­­­Ge0.5I3) to achieve superior performance. Through meticulous experimentation, the suggested model has achieved outstanding results by optimizing several key variables. These variables include the thickness of the absorber layer (CsSn0.5­­­­Ge0.5I3), defect density, and doping densities, as well as the back contact work function and the operating temperature associated with each  Layer. The proposed FTO/PC60BM/CsSn0.5Ge0.5I3/Cu2O/Au solar cell structure surpassed prior configurations by comprehensively examining key aspects such as absorber layer thickness and defect density, doping densities, back contact work, and so on. The structure has been also compared with multiple electron transport elements and concluded that the proposed model functions superior due to the use of PC60BM as an electron transport layer and it has an improved electron extraction procedure. Finally, the proposed model has achieved the optimized values as Jsc of 31.56 mA/cm-2, Voc of 1.12 V, FF of 81.47%, and PCE of 27.72%. 

Perovskite solar cells (PSCs) have achieved remarkable advancements, with power conversion efficiencies (PCE) now exceeding 25%. Recent efforts have focused on developing environmentally friendly, lead-free PSCs using novel, non-toxic or low-toxicity perovskite materials. Among these, Sn-based perovskites are considered a suitable alternative to Pb-based counterparts due to their similar properties. However, the chemical instability of Sn-based perovskites presents challenges that affect their performance in PSC applications. This research investigates the potential of CH3NH3SnBr3 (methylammonium tin bromide) as a promising perovskite material for the absorber layer, in combination with V2O5 (vanadium pentoxide) as the hole transport layer (HTL) and various electron transport layers (ETLs) including C60, IGZO, WS2, and ZnSe. Utilizing SCAPS-1D numerical simulations, the study optimizes the photovoltaic performance of these PSCs by systematically adjusting key parameters such as the thickness, doping density, and defect density of the absorber and transport layers. The results reveal significant variations in PCE across different configurations, depending on the choice of ETL. Among the examined structures, the configuration of FTO/WS2/CH3NH3SnBr3/V2O5/Au exhibited the highest performance, achieving a PCE of 33.54%, an open-circuit voltage (VOC) of 1.10 V, a fill factor (FF) of 88.34%, and a short-circuit current density (JSC) of 34.38 mA cm-2.