Improving Carrier Transport Behavior in a Bilayer ETL for Enhanced Efficiency of Perovskite Solar Cells: An Investigation

Abstract

Perovskite solar cells (PSCs) are currently among the most promising solar cell technologies. A key component influencing their efficiency and stability is the electron transport layer (ETL). This study examined the carrier transport properties of various ETL materials, including TiO2, SnO2, and TiO2/SnO2 bilayer ETLs, to understand their effects on PSC performance. The study proposed a hypothesis that the bilayer design, integrating TiO2 and SnO2, enhances performance, and it used experimental results to substantiate this. Through analysis and discussion of the ETLs, the interface between perovskite (PVSK) and ETLs, and other PSC components, we gained insights into the carrier transport dynamics in PSCs with different ETL configurations. Our findings indicate that the TiO2/SnO2 bilayer ETL structure can significantly improve PSC performance by reducing current leakage, improving carrier transport, and minimizing carrier recombination. This enhancement is quantified by the increase in efficiency from 13.58% with a single-layer TiO2 ETL to 20.49% with the bilayer ETL.