Light intensity dependence of performance of lead halide perovskite solar cells

Abstract

Performance of nanoporous TiO2 based lead iodide perovskite solar cells was investigated under a series of light intensity up to 1.2 sun. The short circuit photocurrent increases linearly with the intensity increase, while the fill factor slightly decreases with the intensity increase. The analysis of logarithmic light intensity dependence of the open circuit voltage revealed a slope of 1.09 kT/q, indicating ideal function of the present solar cells with only bimolecular charge recombination and negligible leakage current. This analysis further suggests that the solar cell performance is improved by simply increasing incident light intensity up to 1.2 sun.