Colored MAPbI3 perovskite solar cells based on SnO2–SiO2 distributed Bragg reflectors

Abstract

Organic–inorganic hybrid perovskite solar cells have attracted significant interest as a novel candidate for building-integrated photovoltaics (BIPV) applications. In particular, coloring methods for perovskite solar cells have been actively studied to meet the aesthetic needs for BIPV. To date, studies based on TiO2–SiO2-based distributed Bragg reflectors (DBRs) have been reported owing to their good color selectivity and low power conversion efficiency (PCE) loss. However, the application of TiO2 layers as DBRs for building exterior can result in serious problem due to their high photocatalytic activity. Therefore, in this study, to overcome this problem, the TiO2 layers in both DBR and electron selective layer in perovskite solar cells are replaced by SnO2 films. SnO2–SiO2 DBRs with various SiO2 thicknesses were synthesized by a simple spin-coating process. By combining DBRs and TiO2-free perovskite devices, blue-, purple-, and yellow-colored perovskite solar cells were successfully fabricated and showed PCEs of 9.52%, 5.99% and 6.85%, respectively.