Fig. 3: Averaged crystal orbital Hamiltonian population analysis of interfacial atomic pairs of TiO2/MAPbI3 (red) and SnO2/MAPbI3 (blue).
From: Efficient electron extraction of SnO2 electron transport layer for lead halide perovskite solar cell
a MAI-terminated and b PbI2-terminated interfaces at the PBE0-TS level. Both in a MAI-termination and b PbI2-terminations, the off-diagonal elements of COHP of SnO2/MAPbI3 are almost twice of TiO2/MAPbI3. The larger orbital hybridizations in SnO2/MAPbI3 at both terminations indicate the superior electron injection to the TiO2/MAPbI3 interface. c Schematic illustration which shows better orbital hybridization between Sn and Pb atoms than Ti and Pb atoms. Left and right geometry indicates MAI-terminated SnO2/MAPbI3 and TiO2/MAPbI3, respectively. The larger orbital hybridizations in SnO2/MAPbI3 at both terminations indicate the superior electron injection to the SnO2/MAPbI3 interface.
