Recent Advances on Tin Oxide Electron Transport Layer for High-Performance Perovskite Solar Cells

Abstract

In recent years, perovskite solar cells (PSCs) have been considered as a game changer for next-generation photovoltaic industry. A surge of attention originates from unprecedentedly rapid enhancement in power conversion efficiency (PCE) to reach over 25%, being competitive with commercialized silicon solar cells. The charge transporting layer, in particular, an electron transport layer (ETL) is one of the key components for high-performance PSCs. The ETL affords efficient extraction of the photo-generated electrons from the perovskite layer, which are subsequently transferred to transparent conduct oxide electrode. Tin oxide (SnO2) is one of the most attractive materials for the ETL due to its wide band gap, high optical transmission, high carrier mobility and high chemical stability. Moreover, the facile low temperature deposition process of SnO2 layer is suitable for mass production as well as versatile applications such as flexible devices. Regardless of excellent intrinsic properties, however, quality of the functional layer and resulting device performance is largely affected by the fabrication process of the material. In this study, we review the studies to utilize the SnO2 ETL for PSCs by adopting various fabrication processes, ultimately to improve efficiency and stability of the PSCs.