Influence of Metal Electrodes on the Charge Extraction of Inverted Perovskite Solar Cells

Abstract

A perovskite solar cell in the inverted configuration was modeled and simulated to investigate the impact of the cathode work function on the cell performance. The model utilized the drift-diffusion current equations, coupled with Poisson’s equation and continuity equations to determine the J-V characteristics, the band diagram, and the external quantum efficiencies. It was found the power conversion efficiency (PCE) tended to decrease with the increasing work functions of the metal cathode. The device using low work function metal Ca delivered the best PCE of 16.7%, whereas the one with high work function Au possessed the lowest PCE of 0.3%. These results were in a close agreement with experiments in literature. Photovoltaic parameters (FF, Jsc, and Voc) showed the same tendency and were responsible for the PCE. The band diagram revealed the formation of Schottky barrier was the main reason for the reduction in Voc, and the external quantum efficiency spectrum showed the adverse effect of the Schottky barrier on the charge extraction.