Direct Charge-Transfer Transition Drives Triplet Generation and Photon Upconversion in 2D Hybrid Perovskites - Weijian Tao; Guohua He; Qingjie Feng; Yiyang Wang; Tianjing Li; Yahui Li; Enzheng Shi; Guangjun Nan; Haiming Zhu (Journal of the American Chemical Society, 2025)