Interface Passivation Of Two-dimensional Perovskites Solar Cells

With the systematic research on Organic-inorganic hybrid halogen perovskite materials,The photoelectric conversion efficiency of perovskite solar cells(PSCs)has been rapidly improved.PCE of PSCs is already comparable to that of silicon solar cells,However the environmental stability of PSCs is poor,which hinders application of PSCs.In order to improve the stability of devices,we mainly focus on perovskite materials and interface materials.The emergence of two-dimensional perovskites material brings good news for improving the stability of PSCs that own to adjustable band gap,abundant organic ion selection,good photoelectric performance and especially good stability.The rapid development of two-dimensional perovskite solar cells(2D-PSCs)is inseparable from many researchers'efforts to improve crystal orientation and phase distribution.However,the selection of interface layer of2D-PSCs and the passivation of 2D perovskite film are also important strategies to improve the device performance,here we will focus on the special requirements of quasi-2D perovskite for the interface layer and modified 2D perovskites film.1)Here,Butylene diamine hydroiodate(BDAI₂)and Butylamine hydroiodate(BAI) were used to modify the 2D perovskite upper layer of AA₂MA₄Pb₅I₁₆.Then respectively DJ or RP 2D perovskite cover layer was formed on the surface.The quasi-2D perovskite films modified by BDAI₂ had the best quality,the open-circuit voltage of 1.22 V was obtained,and the device efficiency was over 18%.The stability of the films was tested by XRD.After 700 hours in air at 20±5?and 75±5%humidity,The modified and unmodified perovskite films were deposited,the stability of BDAI₂modified films was significantly better than others.Finally,the stability conditions of the device are as follows:After 528 hours of the thermal aging process at 60°C in nitrogen atmosphere,the BDAI₂ modified device has not been decayed,and the basic device has been decayed about 8%of original photo-electric conversion efficiency(PCE).2)Here,P3CT-Na/PTAA(Double-hole transport layer,Double-HTL)was used as hole transport layer that combine the advantage of both P3CT-Na and PTAA.The Double-HTL-2D-PSCs(P3CT-Na/PTAA/PEA₂MA₄Pb₅I₁₆(n=5))have better performance,the open-circuit voltage of 1.18 V is obtained,and the device efficiency is over 17.1%.This work have yet to be completed.