Controlling the morphology of the MAPbI3-xClx active layer has remained a challenge towards advancing perovskite solar cells （PvSCs）. Here, we demonstrate that a low temperature additive dripping （AD） treatment st...Controlling the morphology of the MAPbI3-xClx active layer has remained a challenge towards advancing perovskite solar cells （PvSCs）. Here, we demonstrate that a low temperature additive dripping （AD） treatment step, using diphenyl ether （DPE）, can significantly improve the power conversion efficiency （PCE）, compared to the control device using chlorobenzene （CB）, by 15% up to 16.64%, with a high current density （Jsc） of 22.67 mA/cm^2. We chose DPE for its small and appropriate dipole moment to adjust the solubility of the MAPbI3-xClx precursor during the formation of the intermediate phase and the MAPbI3-xClx phase. The low DPE vapor pressure provides a longer processing window for the removal of residual dimethylformamide （DMF）, during the annealing process, for improved perovskite formation. Imaging and X-ray analysis both reveal that the MAPbI3-xClx film exhibits enlarged grains with increased crystallinity. Together, these improvements result in reduced carrier recombination and hole trap-state density in the MAPbI3-xClx film, while minimizing the hysteresis problem typical of PvSCs. These results show that the AD approach is a promising technique for improving PvSCs.展开更多
基金The authors gratefully acknowledge the Fundamental Research Funds for the Central Universities （No. S16JB00060）, the National Science Foundation, NSF- PECASE award （No. CBET-0954985） and the National Natural Science Foundation of China （No. 61575019） for partial support of this work. D. H. also thanks the support from the China Scholarship Council. The AFM SEM used were supported by the Yale Institute for Nanoscience and Quantum Engineering （YINQE） and NSF MRSEC DMR 1119826 for Center for Research on Interface Structures and Phenomena （CRISP）. The GIWAXS obtained at 1W1A, BSRF. The authors further thank scientists of Diffuse X-ray Scattering Station in the experiments for the assistance with GIWAXS measurements, as well as Dr. Yuchuan Shao from the Depai-anent of Electrical Engineering, Yale University for the useful discussion.
文摘Controlling the morphology of the MAPbI3-xClx active layer has remained a challenge towards advancing perovskite solar cells （PvSCs）. Here, we demonstrate that a low temperature additive dripping （AD） treatment step, using diphenyl ether （DPE）, can significantly improve the power conversion efficiency （PCE）, compared to the control device using chlorobenzene （CB）, by 15% up to 16.64%, with a high current density （Jsc） of 22.67 mA/cm^2. We chose DPE for its small and appropriate dipole moment to adjust the solubility of the MAPbI3-xClx precursor during the formation of the intermediate phase and the MAPbI3-xClx phase. The low DPE vapor pressure provides a longer processing window for the removal of residual dimethylformamide （DMF）, during the annealing process, for improved perovskite formation. Imaging and X-ray analysis both reveal that the MAPbI3-xClx film exhibits enlarged grains with increased crystallinity. Together, these improvements result in reduced carrier recombination and hole trap-state density in the MAPbI3-xClx film, while minimizing the hysteresis problem typical of PvSCs. These results show that the AD approach is a promising technique for improving PvSCs.
