A computer-implemented method and system provides output data, wherein the output data includes a performance value of a perovskite-based solar cell. The method includes: (i) receiving input data, wherein the input data includes data from electrical impedance spectroscopy carried out on the solar cell or parts thereof, (ii) applying a trained function to the input data, wherein the output data is generated and (iii) providing the output data. A computer-implemented method also provides a trained function which is able to predict a performance value of a perovskite-based solar cell based on electrical impedance spectroscopy carried out on the solar cell or parts thereof.