Influence of a Compact α-Fe 2 O 3 Layer on the Photovoltaic Performance of Perovskite-Based Solar Cells

Abstract

© 2018 The Electrochemical Society. In this study, uniform and dense iron oxide α-Fe2O3thin films were used as an electron-transport layer (ETL) in CH3NH3PbI3-based perovskite solar cells (PSCs), replacing the Titanium dioxide (TiO2) ETL conventionally used in planar heterojunction perovskite solar cells. The α-Fe2O3films were synthesized using an electrodeposition method for the blocking layer and a hydrothermal method for the overlaying layer, while 2,2’,7,7’-tetrakis (N, N’-di-p-methoxyphenylamine)-9,9’ spirobifluorene (spiro-OMeTAD) was employed as a hole conductor in the solar cells. Based on the above synthesized α-Fe2O3films the photovoltaic performance of the PSCs was studied. The α-Fe2O3layers were found to have a significant impact on the photovoltaic conversion efficiency (PCE) of the PSCs. This was attributed to an efficient charge separation and transport due to a better coverage of the perovskite on the α-Fe2O3films. As a result, the PCE measured under standard solar conditions (AM 1.5G, 100 mW cm−2) reached 5.7%.