Synthesis And Photovoltaic Properties Of Perylene Diimide Derivatives With Aryl Electron-donating Substitutes At Bay Positions

Perylene diimide derivatives(PDIs) have been widely used as electron transport materials(ETMs), organic light-emitting diodes(OLEDs), organic solar cells(OSCs) and organic thin-film transistors (OTFTs) due to their outstanding chemical,thermal. photochemical stability and great optical properties. In the area of OSCs, in order to improve the power conversion efficiency of OSCs, Electron-donoting materails should have narrow bandgaps and deep HOMO energy levels. In this dissertation, based on molecular design, four novel Perylene diimide derivatives with the substitution of rigid electron-donating groups (N-phenyl-carbazolyl and triphenylamino) at the bay positions were synthesized.The thermal, optical and electrochemical properties of the four materials were studied by TGA, optical absorption spectra, and cyclic voltammetry. The PDIs displayed a broad absorption band which extended to the near infrared region. Through cyclic voltammetry, it was disclosed that PDIs possessed appropriate energy levels (HOMO and LUMO) which matched PCBM very well. PDIs were employed as electron donors in organic solar cells. Bulk heterojunction (BHJ) photovoltaic devices with a structure of ITO/PEDOT:PSS/2a-2d:PCBM(1:1, weight ratio)/Al were fabricated and characterized.