Phenyl-C61-butyric acid methyl ester (PCBM) is the most commonly used electron transport layer in inverted perovskite solar cells (IPSCs). However, its electrical performance and passivation ability limit the performance of the device. Recently, Pu Shuping and Cui Guanglei et al. from the Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences have studied and found that introducing an appropriate amount of n-type polymer N2200 into PCBM can simultaneously enhance the electrical performance and passivation ability of PCBM.

This modification of PCBM improved the band alignment and enhanced electron mobility. At the same time, the N2200 polymer contains electron donor groups such as O and S that participate in passivating uncoordinated Pb2+ defects. The PCBM@N2200-based IPSC has an open circuit voltage (VOC) of 1.20 V and a power conversion efficiency (PCE) of 24.53% (certified PCE of 24.05%).

In addition, the corresponding module achieved an efficiency of 20.30% (11.19 cm2), and the PCBM@N2200-based IPSC was able to maintain 96% of its initial efficiency after 500 hours of operation at the maximum power point, which is mainly attributed to the interface passivation, uniformity improvement and hydrophobicity increase brought by the N2200 doping.