| Recent years,the energy issue has become a major concern for the world.The development and use of the clean and renewable energy sources have become the major problems and challenges faced by the human in the new century,especially in the increasingly scarce of the non-renewable resources such as petroleum and coal.Today,the renewable energy sources consist of wind energy,solar energy,tidal energy,and geothermal energy.Among them,the used solar energy been widely has many advantages,such as inexhaustible source,environmentally friendly,non-polluting and recycling.The photovoltaic cells that convert solar energy into electricity directly are the important direction of solar energy utilization.Compared with conventional photovoltaic cell technologies such as monocrysta llinesilicon,polysilicon,and inorganic semiconductors,the organic photovoltaic cells based on organic polymer materials have the advantages of low cost,large area film,flexibility,and light weight.The organic solar cells has become a main research direction in the new generation of solar cells.But the photoelectric conversion efficiency of the organic solar cells is very low.How to improve the photoelectric conversion efficiency is the main research direction of organic solar cells through material design,device optimization,etc.This article focuses on non-fullerene receptors of organic photovoltaic cells.Compared with fullerene receptor materials(PC61BM,PC71BM),the nonfullerene electron acceptor materials have the advantages of wide absorption spectrum and adjustable energy level.The study is as follows:The first chapter of this article mainly introduces the principle and development of organic photovoltaic cells.The second chapter focuses on the manufacture methods and performance characterization of organic photovoltaic cells.In laboratory,the polymer photovoltaic cells are manufactured mainly in the glove box.Through clean the ITO,spin-coating active layer,evaporation electrode et al.In this paper, main use of inverted device research on the performance of photovoltaic cell device.The sized two-dimensional conjugated dithiophene-difluo roben-zothiadiazole copolymer(PBDTT-DFDTB)was used as the donor,and 3,9-bis(2methylene-(3(1,1dicyano methylene)indanone))-5,5,11,11tetrakis(4hexyl-pheyl)-dithieno-[2,3'd:2,3'd']sindaceno[1,2'b:5,6'b'] dithiophene(ITIC)was the non-fullerene acceptor,constructing binary-mixed polymer potovoltaic cells with an efficiency of 8.0%,indicating that the PBDTT-DFDTBT:ITIC system photovoltaic device achieves the same level as the fullerene system.In the absorption spectrum,it can be seen that PBDTT-DFDTBT and([6,6]-phenyl-C71-butyric acidmethylester)PC71-BM and ITIC are complementary,and then ITIC and PC71 BM are used as dual accept materials to systematically study the performance of PBDTT-DFDTBT:PC71BM:ITIC Ternary System.At the same time,the charge carrier mobility,surface morphology and crystallization of the ternary blending system were characterized by space charge-limited current method,atomic force microscope,wide-angle X-ray diffraction and other techniques.The reason for the performance improvement of the device was systematically analyzed and elaborated.The monofluoro-quinoxaline-thiophene copolymer(FTQ)was used as the donor and we use narrow band gap small molecules non-fullerene ITIC-Th as an acceptor material,systematically studied the photovoltaic performance of FTQ: ITIC-Th polymer by changing the preparation conditions for the ratio of the acceptor blend,the film thickness,the thermal annealing temperature and the solvent etc.The results show that the FTQ: ITIC-Th blend has less than 0.3 e V energetic offsets both in Photo-Induced electron transfer and photo-induced hole transfer.The binary FTQ-ITIC-device exhibits the best performance of 8.19 %,35.7% higher than the 5.27% of PC71 BM. |
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