A novel organic electron acceptor, N,N′-dipyrimidinyl-3,4,9,10-perylene-tetracarboxylic diimide (DMP), was designed and synthesized. The molecular structure was characterized by FTIR spectrum and elemental analysis. By cyclic voltammetry measurements, DMP was found to possess a lower LUMO energy level than N,N′-diphenyl-3,4,9,10-perylene-tetracarboxylic diimide due to the stronger electron-withdrawing pyrimidinyl group than the phenyl group. Fluorescence quenching is observed in a dual-layer film consisting of a DMP layer and a C60 layer and was attributed to the charge transfer at the interface due to the energy level offset between DMP and C60.
LIU Bo1,2, SHI MinMin1,2, YANG LiGong1,2, CHEN HongZheng1,2 & WANG Mang1,2 1 State Key Lab of Silicon Materials, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China
The photoconductivities of a series of novel polyacetylene derivatives (PAs) serving as charge generation materials in the single-layered photoreceptors were investigated using photoinduced xerographic discharge technique. It was found that the substitution can improve the photosensitivity of PAs by increasing the conjugation of π electrons. When the substituent is itself photoconductive, the photoconductivity becomes even higher. It can be concluded from cyclic voltammetry that when the HOMO level of the polymer is closer to that of the charge transport material, the photoconduction performance will be better.
We report that the ultraviolet (UV) light induced photochromic behavior of layered organic-inorganic perovskite material of (C4H9NH3)2CuCl4, changed from yellow to brown after irradiation with UV light (10 mW/cm2) and partially recovered through storage in the dark. (C4H9NH3)2CuCl4 exhibited two distinct absorption bands centered at 286 nm (band I) and 384 nm (band II), which were attributed to the photo-induced exciton formed in 2D inorganic layers sandwiched by organic layers. The blue shift of band I from 287 to 269 nm as well as the decrease of the intensity of band I and band II could be found when samples were irradiated under UV light for different length of time. The simultaneous weakening of the intensity of the N-H···Cl hydrogen bond as well as the vibration of the long Cu-Cl bond in the distorted CuCl64-octahedron could be detected from the Fourier transform infrared (FTIR) spectra, which resulted the change of charge distribution of the dissymmetric Cl-Cu···Cl bond and the resulting photochromic behavior.
