Recently, four research groups from the University of Science and Technology of China, namely Yao Hongbin, Fan Fengjia, Lin Yue, and Hu Wei, have collaborated to make significant progress in the field of pure red perovskite light-emitting diodes (LEDs). The team independently invented the Electrical Excitation Transient Spectroscopy (EETA) technology and used it to reveal that hole leakage is the key factor causing the efficiency roll off of pure...