The effect of ultraviolet-ozone(UVO)irradiation on amorphous(am)SnO_(2) and its impact on the photoconversion efficiency of MAPbI3-based perovskite solar cells were investigated in detail.UVO treatment was found to in...The effect of ultraviolet-ozone(UVO)irradiation on amorphous(am)SnO_(2) and its impact on the photoconversion efficiency of MAPbI3-based perovskite solar cells were investigated in detail.UVO treatment was found to increase the amount of chemisorbed oxygen on the am-SnO_(2) surface,reducing the surface energy and contact angle.Physicochemical changes in the am-SnO_(2) surface lowered the Gibbs free energy for the densification of perovskite films and facilitated the formation of homogeneous perovskite grains.In addition,the Fermi energy of the UVO-treated am-SnO_(2) shifted upwards to achieve an ideal band offset for MAPbI3,which was verified by theoretical calculations based on the density functional theory.We achieved a champion efficiency of 19.01% with a statistical reproducibility of 17.01±1.34% owing to improved perovskite film densification and enhanced charge transport/extraction,which is considerably higher than the 13.78±2.15% of the counterpart.Furthermore,UVO-treated,am-SnO_(2)-based devices showed improved stability and less hysteresis,which is encouraging for the future application of up-scaled perovskite solar cells.展开更多
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(2020R1F1A1068664)supported by the Defense Challengeable Future Technology Program of the Agency for Defense Development,Republic of Korea.
文摘The effect of ultraviolet-ozone(UVO)irradiation on amorphous(am)SnO_(2) and its impact on the photoconversion efficiency of MAPbI3-based perovskite solar cells were investigated in detail.UVO treatment was found to increase the amount of chemisorbed oxygen on the am-SnO_(2) surface,reducing the surface energy and contact angle.Physicochemical changes in the am-SnO_(2) surface lowered the Gibbs free energy for the densification of perovskite films and facilitated the formation of homogeneous perovskite grains.In addition,the Fermi energy of the UVO-treated am-SnO_(2) shifted upwards to achieve an ideal band offset for MAPbI3,which was verified by theoretical calculations based on the density functional theory.We achieved a champion efficiency of 19.01% with a statistical reproducibility of 17.01±1.34% owing to improved perovskite film densification and enhanced charge transport/extraction,which is considerably higher than the 13.78±2.15% of the counterpart.Furthermore,UVO-treated,am-SnO_(2)-based devices showed improved stability and less hysteresis,which is encouraging for the future application of up-scaled perovskite solar cells.
