Anisotropic charge transport and optoelectronic properties of wide band gap organic semiconductors based on biphenyl derivatives: A computational study

摘要

The electronic structures and the charge transport properties of the biphenyl derivatives were calculated using density functional theory (DFT). The values of ionization potential (IP) of all the compounds were found in the range of 5.4-6.6 eV inferring the fact that the studied compounds held considerable air-stability properties. Moreover, lower values of hole-injection barrier as compared to those of electron-injection barrier implied that the investigated compounds were p-type semiconductors. The Hirshfeld Surface analysis depicting the distribution of surface charge in between the molecular layers of the crystals revealed that the principal interactions were mostly due to the C center dot center dot center dot H/H center dot center dot center dot C and H center dot center dot center dot H contacts for all the studied crystals. Bathochromic shifts were observed in absorption spectra of the compounds due to the substitution of different functional groups. The excitation energy and electronic HOMO-LUMO gap > 3 eV inferred the compounds to be wide band gap semiconductors. Further, the electronic band structure calculations for all the crystals ensued the band gap of the studied crystals in the range of 2.3-2.4 eV.