D-A-A和D-A-Ar线型和星型有机供体材料的分子构筑、合成及其光伏性能的研究

As solution-processed bulk-heterojunction organic solar cells (BHJ-OSC) exhibit a key science problem of low power conversion efficiency, the linear and star organic photovoltaic donor materials with the D-A-A1and D-A-Ar combined structures are designed and synthesized, which contain the donor (D) unit of triarylamine or carbazole or benzothiophene derivative, the first acceptor (A) unit of 2,1,3-benzothiadiazole or 2,5,-dialkyl-3,6-(dithiophen-2-yl)-diketopyrrolo- pyrrole or benzotriazole derivative, the second acceptor (A1) unit of cyanoacrylate and the aromatic hydrocarbon (Ar) unit of pyrene or phenanthrene. This class of photovoltaic donor materials should present narrow energy-band, wide spectral response and high carrier mobility. The relationship among the photovoltaic properties and donor molecular structures and BHJ-OSC structures are studied. The high-efficiency novel D-A-A1and D-A-Ar units-based organic photo- voltaic donor materials and their solution-processed BHJ-OSC will be obtained. This project is available for revealing the designed rule of organic photovoltaic donor molecules with narrow energy-band, wide spectral response and high carrier mobility, as well as high-efficiency photo- electron conversion mechanism. Importantly, it is significant for developing novel organic photo- voltaic materials with autonomous intellectual property and obtaining high-efficiency solution- processed BHJ-OSC, further promoting theoretical and applied studies of organic photovoltaic materials and their BHJ-OSC.

针对溶液加工型本体异质结有机太阳能电池(BHJ-OSC)能量转移效率低等关键科学问题，设计合成含三芳胺（或咔唑、苯并噻吩）衍生物供体(D)单元、二噻吩基吡咯并吡咯二酮（或苯并噻二唑、苯并三唑）衍生物受体(A)单元、氰基酯受体(A)1单元、芘（或菲）等稠环芳烃(Ar)单元的，具有D-A-A1和D-A-Ar组合结构的、窄带隙、宽光谱带响应和高迁移率的线型和星型有机光伏供体材料，研究含D-A-A1和D-A-Ar组合结构的线型和星型有机光伏供体材料的分子结构及其BHJ-OSC器件结构与光伏性能的关系，获得高效的具有D-A-A1和D-A-Ar组合结构的有机光伏供体材料及其BHJ-OSC。项目的实施将有利于揭示窄带隙、宽光谱带响应和高迁移率的有机光伏材料的分子设计规律以及高效光-电转换的机理；对于发展我国具有知识产权的有机光伏供体材料，促进有机太阳能电池的理论的与应用研究具有重要意义。

有机太阳能电池由于具有材料多样性、制备成本低和可大面积柔性加工等优点已成为新能源领域的研究热点。开发新型光活性层材料和优化太阳能器件结构是高性能有机太阳能电池的研究主题。本项目针对有机太阳能供体材料存在的光谱响应范围窄、器件光电转换效率低等关键科学问题，展开了窄带隙、宽光谱响应和高载流子迁移率的有机光伏供体材料的分子构筑方法研究，探索了新型高效有机光伏供体材料的光电性能及其分子设计规律、器件结构与光伏性能的关系，获得了具有供体-受体-受体（D–A–A）和供体-受体-平面芳烃（D–A–Ar）结构单元的线型和星型高效有机光伏材料，主要包括D(A–Ar)n (n=1, 2, 3)，Ar(A–Arʹ)n (n=1, 2, 3)，Ar(A–D)2和D(A–Aʹ)2等四种构建方式的有机光伏材料。其中，基于Ar(A–D)2线型小分子ThDPP2-Py的有机太阳能电池(OSCs)器件的能量转化效率(PCE)为5.88%；基于D(A–Aʹ)2线形小分子BDTT(TPD–DPP)2器件的PCE为4.25%，其短路电流(Jsc)是基于单一受体分子 BDTT(DPP)2器件的3.1倍；基于D(A–Ar)n星型小分子TPA(BT–T–3Cz)3器件的PCE为 5.07%，这也是目前报道的高效率星型有机小分子供体材料之一；基于Ar(A–Arʹ)n星型小分子NT(DPP-PN)3器件的PCE为 3.69%。. 研究表明，有机光伏材料的分子构建方式对光伏材料的性能具有显著的影响。基于D–A–A和D–A–Ar 结构单元的线型和星型分子能实现窄带隙、宽光谱响应和高载流子迁移率，是很有发展潜力的有机光伏供体材料。本研究对于进一步揭示高能量转换效率、高稳定性的有机太阳能电池的构筑规律，实现溶液加工型OSCs的高效能量转化具有积极的指导意义。