Influence of a Compact α-Fe2O3 Layer on the Photovoltaic Performance of Perovskite-Based Solar Cells

In this study, uniform and dense iron oxide alpha-Fe2O3 thin 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 alpha-Fe2O3 films 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 alpha-Fe2O3 films the photovoltaic performance of the PSCs was studied. The alpha-Fe2O3 layers 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 alpha-Fe2O3 films. As a result, the PCE measured under standard solar conditions (AM 1.5G, 100 mW cm(-2)) reached 5.7%. (c) 2018 The Electrochemical Society.