Effect of Carrier Transport in NiO on the Photovoltaic Properties of Lead Iodide Perovskite Solar Cells

Abstract

The effect of the NiO_x thickness on the photovoltaic properties in planar type lead iodide perovskite solar cells consisted of Tin-doped indium oxide (ITO)/NiO_x/Perovskite/Phenyl-C61-Butyric-Acid-Methyl Ester (PCBM)/Ag was investigated. For films ranging from 35 nm to 120 nm in the thickness, the NiO_x thickness was found to be not crucial in fill factor and open circuit voltage. Calculations of the carrier flux in NiO_x, estimated from Einstein-Smoluchowski relation and Fick’s first law, found the carrier transport ability of the NiO_x to fully compensate the photo-generated current density in perovskite layers and the theoretical current density ca. 26 mA cm⁻². The favorable physical properties such as mobility and thickness were also estimated for effective carrier transport in perovskite solar cells assuming that the carrier density is 10¹⁵ cm⁻³.