“…All elements of Bi, Cs, Pb, and Br may be observed, indicating the formation of Bismuthene/CsPbBr 3 QDs, which is consistent with the FTIR and TEM characterization in Figure a,c. The high-resolution of Bi 4f spectra of Bismuthene and Bismuthene/CsPbBr 3 QDs are shown in Figure a. , The main peaks of Bi 4f 5/2 and Bi 4f 7/2 are located at 161.86, 158.80, and 163.53, 158.12 eV for Bismuthene/CsPbBr 3 QDs and Bismuthene, respectively. The peaks of the oxidized Bismuthene (Bi x O y ) locate at 164.09, 159.60 and 165.31, 159.94 eV for Bismuthene/CsPbBr 3 QDs and Bismuthene, which are assigned to Bi x O y 4f 5/2 and Bi x O y 4f 7/2 , respectively.…”