A theoretical investigation of low energy band gap polymers: polythiophene systems

作者:Tai Chin Kuen; Yeh Pao Ling; Chang Chun Chi; Chen Wen Hao; Wu Rong Hou; Chou Yu Ma; Wang Bo Cheng*
来源:Research on Chemical Intermediates, 2014, 40(6): 2355-2362.
DOI:10.1007/s11164-014-1612-y

摘要

Recently, the organic synthesis and electronic device applications of pi-conjugated polymer-based materials with low energy band gap (below 2 eV) and high values of incident photon to current efficiency have been presented. In the present study, the physical properties of polythiophene (PTH) and its derivative systems (PTs) were investigated as pi-conjugated low energy band gap polymers. Density functional theory with periodic boundary condition (PBC), the B3LYP functional, and the 6-31G(d) basis set was applied to determine their geometric and electronic structures and corresponding energies (E (HOMO), E (LUMO), and E (g) = E (LUMO) - E (HOMO)) from the monomer of thiophene and its derivatives for one-dimensional (1D) extension to polymer. The effects of 3-substitution in PTs including electron-donating (CH3-, C6H13-, OH-, Cl-, OCH3-, and CHO-) and electron-withdrawing groups (Cl-, CHO-, CN-, NO2-, CF3-, and COOH-) compared with PTH were investigated. According to the calculation results, PTs with electron-donating and electron-withdrawing substituents should exhibit red- and blue-shifts, respectively, compared with PTH. These calculation results show good agreement with experimental data and provide further information for molecular design considerations.

  • 出版日期2014-7