Accessible spectral calibration of multi-LED solar simulators for tandem I – V measurement

Reproducing the AM1.5G reference spectrum using solar simulators in the laboratory is essential for accurate and transparent reporting of the I – V performance of perovskite-based tandem solar cells, a fast-growing technology approaching commercialization. The International Electrotechnical Commission (IEC) has specified the spectral calibration requirements for tandem devices in IEC 60904-1-1: Photovoltaic devices – Part 1-1: Measurement of current-voltage characteristics of multi-junction photovoltaic devices . However, practical implementation of these standards using multi-LED solar simulators can be challenging. This study shares a method to calibrate multi-LED solar simulators for tandem devices, with code implementation. This method was developed to satisfy the IEC-defined mismatch factor ( M ) and matching factor ( Z ) thresholds, which quantify how accurately the solar simulator reproduces the reference spectrum for tandem device measurement. The method is validated on three perovskite–silicon tandem solar cells, all of which achieved |1– M |