Toward a Diagnostic Method for Efficient Perovskite Solar Cells Based on Equivalent Circuit Parameters

The equivalent circuit model is one of the essential tools for revealing information about the material characteristics, working mechanisms, and operation state of perovskite solar cells. However, it is still challenging to accurately obtain the equivalent circuit parameters of the highly efficient solar cells with a power conversion efficiency more than 22%. In this work, we proposed a new scheme to estimate all the parameters of the high-performance solar cells only from their current-voltage curves by reasonably combining the traditional analytical method and the parameter optimization method. Then, we applied the proposed method to analyze the equivalent circuit parameters of a typical efficient perovskite solar cell under different light intensities and aging times. Through the parameters, we succeeded in bridging photovoltaic parameters and the structural, morphological, and optoelectronic changes of the solar cells. In particular, the proposed method is compatible with the notorious current-voltage hysteresis. To test the method further, it is compared with two typical approximate methods commonly used recently. By comparison, the proposed approach is simple, reliable, and insensitive to the initial values. Moreover, limitations and precautions for the traditional methods are given to ensure their effectiveness. Finally, we note that the proposed approach of this work provides a feasible solution to conduct real-time monitoring and analysis of the high-performance solar cells.