Bulk Heterojunction Interface Regulation And Its Application In Organic Solar Cells

As a kind of clean energy,solar energy is inexhaustible.The exploration,utilization and research of solar cells have been favored by researchers at home and abroad.Through the development and research of many generations of researchers,solar cells have undergone several changes and varied types.In recent years,fullerene n type organic semiconductor represented by PCBM has been widely used in organic polymer active layer,and to regulate the activity level,to the development of new materials,active layer manufacture and so on many kinds of methods to improve the performance of the device is battery,and based on polymer fullerene polymer PCE already more than 11%.However,in the last two years,due to the good thermal stability,light and chemical stability,easy to adjust energy levels and design synthesis of non-Fuller materials,more and more attention has been paid to the research and exploration.The bulk heterojunction is the basis of the organic solar cell and is the guarantee of high power conversion efficiency of the solar cell.Therefore,we have studied the interfacial regulation of bulk heterojunction and the application of bulk heterojunction in organic solar cells by several methods,in order to improve the performance of solar cells.The specific method is as follows:?1?Donor polymers were prepared with benzotriazole as electron donor group and benzodithiophene as electron-withdrawing group,and the active layer was prepared with PC₇₁BM as acceptor.The spin 1/2 galvanoxy radicals,in order to regulate the interface morphology of bulk heterojunctions.And to study the change the self-assembly order,interface morphology,microcrystalline particle size and other factors of carrier transport and collection.And change the performance of the solar cell device.With benzotriazole as electron donor group and benzodithiophene as electron-withdrawing group,the PCE increased by up to 79%after addition of spin1/2 radicals.?2?The acceptor polymers were synthesized from NDI,PDI,DTP and DTS.By calculating the dipole moment and polarizability of non-fullerene acceptor polymers,we can identify different receptor polymer systems and determine the effect of polarizability of different receptor polymers on the performance of photovoltaic devices.Different donor and acceptor polymers were selected for the design and synthesis of high performance solar cells.?3?Four fluorinated donor polymers were prepared and active layer was prepared using PC₇₁BM as the acceptor material.Comparing the number of fluorine atoms introduced into the polymer and the performance parameters of the polymer-fullerene BHJ solar cell,it was found that the transient fluorescence lifetime of polymers containing two fluorine atoms is significantly longer than that of one fluorine atom,thus its PCE is higher.And in the P9-P12:PC₇₁BM solar cell device,P10 the best photovoltaic performance,up to 3.2%of the PCE.So the introduction of fluorine atoms in the polymer has a high application prospect for improving the PCE and lifetime of the solar cell.In addition,our study found that the polarizability and dipole distance can be used to screen different donor polymers and introduce fluorine atoms for the design and synthesis of high performance solar cells.