A review of coating tin oxide electron transport layer for optimizing the performance of perovskite solar cells

Abstract

Perovskite solar cells (PSCs) have recently emerged as a transformative technology in the photovoltaic sector, drawing considerable attention due to their rapid advancements in power conversion efficiency (PCE), which now exceeds 26.7 %. This efficiency level places them in direct competition with conventional silicon-based solar cells. A key element in ensuring the high performance of PSCs is the charge transport layer (CTL), particularly the electron transport layer (ETL). The ETL plays a crucial role by efficiently collecting photo-generated electrons from the perovskite layer and transferring them to the transparent conductive oxide electrode. Among the ma- terials used for ETLs, tin oxide (SnO 2) stands out for its wide band gap, excellent optical transparency, superior carrier mobility, and remarkable chemical stability. Additionally, SnO2 can be deposited at low temperatures, making it ideal for mass production and adaptable for applications such as flexible devices. Despite its inherent advantages, the overall performance and quality of the ETL, and thus the device itself, are heavily influenced by the fabrication process. This study reviews recent approaches to fabricating SnO 2 ETLs in PSCs, with a focus on optimizing efficiency and long-term stability