Y. He, I. Abdellaoui, M. Abdel-Shakour, T. H. Chowdhury, M. A. Kamarudin, A. F. Nogueira, Q. Shen, S. Hayase, A. Islam and T. Sakurai. Study of open circuit voltage loss mechanism in perovskite solar cells, Japanese Journal of Applied Physics 60, SBBF13 (2021).