Synthesis And Performance Of Novel Fluorinated Donor Materials In Solar Cells

With the development of donor material of polymer solar cell(PSC),more and more new material get the wide attention of the researchers,the power conversion efficiency((PCE)of PSC is also constantly improved.Although the highest power conversion efficiency of polymer solar cells is reached 12%,it is still far from the traditional inorganic solar cells.At present,researchers have founda lot of ways to increase the performance of PSC,such as searching new donor materials of active layer,which has wider photoresponse range,higher carrier mobility and more matched energy levels.In this dissertation,a A series of polymers were synthesis based on benzo[1,2-b:4,5-b’]thiophene,fluorinated benzothiadiazole and derivatives of perylene by still coupling.And the thermal stabilities and optical properties of these polymers were researched.In chapter 2,a new D-A polymer comprising of 2,2’--bithiophen donor unite and 4,7-di(thien-2-yl)-5,6-difluorobenzo-[2,1,3]thiadiazole acceptor unite was synthesized via stille coupling reaction.The molecular weight of polymer was characterized by GPC,the chemical structure of polymer was characterized by ~1H NMR and FT-IR,Besides,their thermal stabilities,photophysical and electrochemical properties were analyzed.The results showed that the polymer has excellent thermal stability and wider photoresponse range.It also shows excellent electrochemical performance and has better energy levels and narrower band gaps.This polymer is suitable as donor material of polymer solar cell active layer.In chapter 3,a kind of donor unite benzo[1,2-b:4,5-b’]thiophene(BDT)was synthesized,then fluorinated benzothiadiazole and thiophene as acceptors were introduced into the BDT unite via stille coupled reaction.This new polymer was characterized by a series of methods.The structure of the polymer was characterized by NMR and FT-IR.It was determined that the polymer was synthesized.The molecular weight of polymer was characterized by GPC.The thermal decomposition temperature of the polymer was 307°C,and the absorbance range was existed in 300-600 nm..The polymer has low optical band gap(about1.95 eV)and the HOMO energy level and LUMO energy level were about-5.38 eV and-3.49eV.It is also suitable as a donor material for active layer of polymer solar cell.It provides more optional directions for polymer solar cell materials.