Bayesian Estimation of Equivalent Circuit Parameters of Photovoltaic Cell with S‐Shaped Current–Voltage Characteristic

Abstract

An S‐shaped current–voltage characteristic is frequently observed in a photovoltaic cell using emerging materials such as organic semiconductors and organic–inorganic perovskite materials. The opposed two‐diode equivalent circuit model, whose explicit analytical solution is known, can reproduce the S‐shaped characteristic. However, since the number of parameters is as high as eight, it is not easy to extract the equivalent circuit parameters from experimental data by curve fitting. Herein, the Bayesian estimation in extracting the equivalent circuit parameters of the opposed two‐diode model is demonstrated. Unlike the traditional nonlinear least‐squares method, the Bayesian estimation practically does not require any tuning of the initial values and gives the information on the error of the estimates.