Research On The Cathode Interface Modification And Performance Of Ternary Non-Fullerene Acceptor Of Organic Solar Cells

Organic solar cells?OSCs?have attracted considerable attention because of their unprecedented features that provide completely new device functionalities and offer advantages over the rigid and fragile existing inorganic-based solar cells,such as light weight,foldability,wearability,biocompatibility,and easy integration on curved surfaces.However,compared to inorganic solar cells,the biggest disadvantage of organic solar cells is low efficiency,which is not conducive to commercial development.Therefore,this paper mainly improves the efficiency of organic solar cells from two aspects.One is to improve the interface,and the other is to improve the performance of the device by using ternary strategy.This article mainly uses the work of the three systems to elaborate in detail:First,two kinds of fullerenes interface FPNOH and FBPNOH are applied to the PTB7-Th:PC₇₁BM system,and the interface is treated by thermal annealing and solvent annealing.The efficiency of the standard device based on the ZnO interface is 8.30%,and the annealed device based on the fullerene interface is more efficient than the ZnO interface device.After solvent annealing,the maximum device efficiency can reach 10.05%.This indicates that solvent annealing is an effective way to improve device efficiency.Secondly,in order to improve the efficiency of the device,we add the strong crystalline small molecule RTCN into the polymer system PTB7-Th:N2200 to form a ternary all-polymer solar cell.The introduction of strong crystalline RTCN as a acceptor material is beneficial to the formation of a suitable phase separation in the blend membrane,the formation of a smooth energy gradient,which can inhibit the charge recombination of the bimolecular charge and lead to more effective charge generation and transmission,and eventually lead to a significant increase in the efficiency of the device.Finally,in order to better explore the ternary all-polymer solar cell,we add the small molecular acceptor 2PDINB based on the PDI unit into the polymer system PTB7-Th:N2200,in which N2200is a polymer acceptor based on the NDI unit,and the two highly planar and easily aggregated non fullerene acceptor binding can obtain a good phase separation morphology,which provides a new idea for our later research.