Exploring Optimal CsGeI₃ Perovskite Performance and Investigating Suitable Hole Transport Layers for Solar Cell Optimization

This paper provides a detailed analysis of perovskite solar cells (PSCs) with a CsGeI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> absorber layer, using SCAPS-1D simulation for evaluation. The study investigates the FTO/TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>/CsGeI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>/HTL structure and explores several hole transport layers (HTLs) to enhance device performance. By optimizing the thickness and acceptor density of the absorber layer in combination with different HTLs, the research demonstrates significant improvements in efficiency. The use of Cu<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O as an HTL resulted in an impressive power conversion efficiency (PCE) of 37.39%, exceeding the previous best of 35.91%. This investigation offers new insights into the role of HTL variations and absorber layer optimization, positioning CsGeI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>-based PSCs as a promising technology for future solar applications.