Enhanced Performance And Stability Of Perovskite Solar Cells Using Doping And Interface Modification

Recently,perovskite solar cells(PSCs)have attracted much attention due to its impressive certified power conversion efficiency(PCE)of 24.2%.However,the stability and PCE of PSCs need to be further improved in the process of commercialization.In this work,strategies including strontium doped nickel oxide(Sr:NiO_x),silvernanoparticlesdopednickeloxide(Ag@NiO_x)and poly(9-vinylcarbazole)(PVK)modified the interface of perovskite/PCBM have been applied to improve the photovoltaic performance and stability of PSCs.(1)Sr:NiOx films were prepared through low temperature sol-gel method and applied as hole transport layer for p-i-n configuration PSCs.The hole extraction and transport abilities of Sr:NiOx films are better than NiOx films.Furthermore,the reduced surface roughness of Sr:NiOx is beneficial to grow the compact perovskite films.PSCs prepared with Sr:NiOx hole transport layer got highest PCE of 20.07%,with negligible hysteresis.Unencapsulated devices prepared with Sr:NiOx hole transport layer maintained 60%of the original PCE value while the reference devices maintained only 35%the original PCE value ageing for 100 days in the air.(2)Ag nanoparticles(Ag NPs)and PVK were respectively used to modify the hole transport layer and interface of perovskite/PCBM in PSCs.Doping Ag NPs into NiOx film improves its hole extraction and transport abilities.The improved wettability of Ag@NiO_x layer helps to improve the crystallization of perovskite layer.The perovskite films were prepared by one-step solvent engineering.The PVK added into anti-solvent improved the crystallinity of perovskite layer and the contact property of perovskite/PCBM interface due to the uniform perovskite surface.PSCs modified with both Ag NPs and PVK got highest PCE of 19.09%,and maintained 80%of the original PCE value after 50 days in air,which is higher than that(40%)of the reference cells.Under 85?thermal tests for 3 hours,PSCs modified with both Ag NPs and PVK maintained 87%of the original PCE,while the reference cells maintained only 11%of the original PCE.