摘要
Though various efforts on modification of the electrodes are still undertaken to improve the efficiency of perovskite solar cells, attributing to the large scope of these methods, it is of significance to unveil the working principle systematically.Herein, we construct inverted perovskite solar cells based on ITO/PEDOT:PSS/CH_3NH_3PbI_3/PC_(61)BM/buffer metal/Al.Through choosing different buffer metals to tune work function of the cathode, contact nature of the active layer with the cathode could be well manipulated.In comparison with device using Au/Al as the electrode that shows an unfavorable band bending for conducting the excited electrons to the cathode, the one with Ca/Al presents a dramatically improved efficiency over 17.1%, ascribing to the favorable band bending at the interface of the cathode with the active layer.Details for tuning the band bending and the according charge transfer mechanism are given in a systematic manner.Thus, a general guideline for constructing perovskite photovoltaic devices efficiently is provided.
Though various efforts on modification of the electrodes are still undertaken to improve the efficiency of perovskite solar cells, attributing to the large scope of these methods, it is of significance to unveil the working principle systematically.Herein, we construct inverted perovskite solar cells based on ITO/PEDOT:PSS/CH_3NH_3PbI_3/PC_(61)BM/buffer metal/Al.Through choosing different buffer metals to tune work function of the cathode, contact nature of the active layer with the cathode could be well manipulated.In comparison with device using Au/Al as the electrode that shows an unfavorable band bending for conducting the excited electrons to the cathode, the one with Ca/Al presents a dramatically improved efficiency over 17.1%, ascribing to the favorable band bending at the interface of the cathode with the active layer.Details for tuning the band bending and the according charge transfer mechanism are given in a systematic manner.Thus, a general guideline for constructing perovskite photovoltaic devices efficiently is provided.
引文
[1]S.Yue,S.Lu,K.Ren,Dr.K.Liu,M.Azam,D.Cao,Z.Wang,Y.Lei,S.Qu,Z.Wang.Small,2017,DOI:10.1002/smll.201700007.