基于1,2,4-三唑-5-硫酮有机小分子的合成与光伏性能研究

合成具有优异性能的给体材料是有效提高有机小分子太阳电池效率的重要途径，项目拟合成三个不同系列的D-A型有机共轭分子。以苯并稠杂环(苯并二噻吩、苯并二呋喃、噻吩[2,3-f]苯并呋喃)为给电子单元，1,2,4-三唑-5-硫酮为吸电子单元，连二噻吩为π桥，设计合成A-D-A型共轭小分子。以苯并稠杂环为给体单元，1,2,4-三唑-5-硫酮为受体单元，分子封端为烷基连二噻吩，合成D1-A-D2-A-D1型共轭小分子。最后，构建并合成给体单元为苯并稠杂环但含有多个受体单元有机太阳电池材料，其中苯并噻二唑、苯并三唑为辅助吸电子单元，1,2,4-三唑-5-硫酮为端基吸电子单元。研究分子结构，共混形貌与太阳电池性能的关系，并对太阳电池界面修饰，动力学和热力学等机制机理进行研究。课题旨在为设计合成具有低带隙、低HOMO能级、宽光谱吸收的高性能太阳电池材料提供科学理论依据和实践参考。

The important strategy to improve the efficiency of small molecule organic solar cell is to synthesize excellent donor materials. In this proposal, we design three different series of D-A conjugated small molecules. The structures of molecules are as follows: A-D-A type small molecules with benzo-fused heterocycle [benzodithiophene (BDT), benzodifuran (BDF), thieno[2,3-f]benzofuran (TBF)] as donor unit, 1,2,4-triazole-5-thione as accepter unit, 2,2’-bithiophene as π bridge were developed; D1-A-D2-A-D1 type small molecules with benzo-fused heterocycle as donor unit, 1,2,4-triazole-thione as acceptor unit, 5-hexyl-2,2’-bithiophene as terminal group were designed; Another new small molecules containing multiple acceptor units were synthesized with benzothiadiazole or benzotriazole as auxiliary acceptor unit, 1,2,4-triazole-thione as terminal acceptor unit. The relationship between molecular structures, blend morphology and photovoltaic properties will be investigated. Furthermore, interface modifications, kinetics and thermodymanics mechanisms in the devices will be deeply explored. This work may provide some significant guidelines for designing high performance photovoltaic materials with low bandgap, deep HOMO level and broad absorption.