含吡咯并吡咯二酮、异靛蓝衍生物有机材料的合成和光伏性能的分析-高分子化学与物理专业论文.docxVIP

湘潭大学硕士论文 湘潭大学硕士论文 II II Abstract Solar energy has attracted extensive attention by the world due to the advantages of widely used, environmental friendly and inexhaustible. Currently solar cells based on silicon have been used in reality, but due to its high cost and environmental pollution limit its wide range of applications. Organic solar cells (OSCs) have attracted attention in academica due to the advantage of light weight, low cost, flexible and large area production. While the active layer of organic solar cell is generally made of electron-donating organic materials and high-electron-affinity fullerene derivatives, and the electron-donating organic materials which consist of electron-donating donor unit (D) and the electron-affinity acceptor unit (A) have been developed widely. The diketopyrrolopyrrole (DPP) unit and isoindigo derivatives have been widely used in OSCs due to its broad and strong absorption in the UV-visible. We successfully designed and synthesized three small molecules based on DPP core with different terminal groups, also designed and synthesized a new π -extended isoindigo derivative, and applied in small molecule bulk heterojunction (SMBHJ) solar cells. We investigated the structural characterization and photovoltaic performance of the small molecules, and the results as follows: We synthesized three new low bandgap donor-acceptor-donor (D-A-D) type organic small molecules (M1-M3). Small molecules consisting of naphthalene end-groups and DPP (M1 and M3) and one reference molecule consisting of thiophene end-groups and DPP (M2) were synthesized. Then we investigated the optical, electrochemical, thermal and photovoltaic properties of these molecules. These materials possess strong absorption at 475-750 nm and low-lying HOMO levels (?5.28 eV ~ ?5.35 eV). SMBHJ solar cells based on M1-M3/PC71BM blends (1:1, w/w) demonstrate power conversion efficiencies (PCEs) as high as 2.59%, and naphthalene-ended M1 and M3 show higher photovoltaic perfor