Evaluation of the photocurrent value for poly(2,5-dicyano-p-phenylene-vinylene)-co-(p-phenylene-vinylene) (DCN-PPV/PPV)

摘要

A method to obtain poly(2,5-dicyano-p-phenylene-vinylene)-co-(p-phenylene-vinylene) (DCN-PPV/PPV) block copolymer was developed. The structural characteristics of the copolymer and its capability to generate a photocurrent were evaluated. IR spectra indicate the complete conversion of precursor copolymer into DCN-PPV/PPV at 250 A degrees C under low-pressure conditions. The DCN-PPV/PPV polymer optical band gap was determined based on the observed UV-Vis spectral data by using Tauc's equation. The two linear regions in the Tauc curve (E-g = 2.63 eV and 2.02) revealed the formation of a block copolymer. Thermal analysis showed that DCN-PPV/PPV has a higher stability than PPV and starts to degrade at 317 A degrees C in air. The electronic parameters of DCN-PPV/PPV (IP = 5.25 eV, EA = 3.30 eV, and E-g = 1.95 eV) indicate that the cyano groups reduce the LUMO energy level without affecting the HOMO energy by much. DCN-PPV/PPV photoactivity measurements show higher photocurrent values compared to those for PPV.