Round-Robin Inter-Comparison of Maximum Power Measurement for Metastable Perovskite Solar Cells

Perovskite solar cells (PSCs) are expected to be one of the next generation photovoltaics. However, reliable measurements of the power conversion efficiency (PCE) of PSCs are challenging as changes in the electrical properties occur during the conventional I-V curve measurements. In order to solve this problem, several methods to maximize the accuracy have been developed, but consistency between these methods has not been verified. In this paper, a round-robin inter-comparison of the maximum power measurements for metastable perovskite solar cells has been performed among three public laboratories in Japan using several methods. The maximum powers determined by the three laboratories using the conventional I-V curve measurement technique defined in IEC 60904-1 were compared to each other. The relative standard deviation of the maximum power was 4.76%. The maximum power point tracking (MPPT), steady-state (or stabilized) power output (SPO) and dynamic I-V measurements were also performed as the steady-state measurements of the maximum power. An excellent consistency was found to exist between the maximum powers obtained by the MPPT, SPO and dynamic I-V methods. The relative standard deviation of P (max) determined by the MPPT method at KISTEC and AIST was 1.25%.