Computational Probing of Tin-Based Lead-Free Perovskite Solar Cells: Effects of Absorber Parameters and Various Electron Transport Layer Materials on Device Performance.

Abstract

Tin-based perovskite solar cells have gained global research attention due to the lead toxicity and health risk associated with its lead-based analog. The promising opto-electrical properties of the Tin-based perovskite have attracted researchers to work on developing Tin-based perovskite solar cells with higher efficiencies comparable to lead-based analogs. Tin-based perovskites outperform lead-based ones in areas such as optimal band gap and carrier mobility. A detailed understanding of the effects of each parameter and working conditions on Tin-based perovskite is crucial in order to improve efficiency. In the present work, we have carried out a numerical simulation of a planar heterojunction Tin-based (CH3NH3SnI3) perovskite solar cell employing a SCAPS 1D simulator. Device parameters, namely, the thickness of the absorber layer, the defect density of the absorber layer, working temperature, series resistance, and metalwork function, were exclusively investigated. ZnO was employed as the ETL (electron transport layer) material in the initial simulation to obtain optimized parameters and attained a maximum efficiency of 19.62% with 1.1089 V open circuit potential (Voc) at 700 nm thickness (absorber layer). Further, different ETL materials were introduced into the optimized device architecture, and the Zn2SnO4-based device delivered an efficiency of 24.3% with a Voc of 1.1857 V. The obtained results indicate a strong possibility to model and construct better-performing perovskite solar cells based on Tin (Sn) with Zn2SnO4 as the ETL layer.