Impact of ZnO Decoration on Electronic Properties of Alkyl Substituted Thiophene–Carbazole Copolymer

Abstract

This study analyzes the impact of zinc oxide (ZnO) decoration on the structure, stability and electronic properties of the alkyl-substituted thiophene-vinyl carbazole (3-MeTH-VCZ) copolymer, employing density functional theory (DFT)-based quantum atomistix toolkit (ATK) software. This analysis shows a negative interaction energy between the ZnO and the pristine 3-MeTH-VCZ, facilitating substantial charge transfer. Furthermore, the composite (3-MeTH-VCZ-ZnO) formed by the decoration of ZnO in the pristine 3-MeTH-VCZ shows improved electronic properties compared to its pristine counterpart. This improvement is evidenced by an approximate 62% reduction in the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap, confirmed by shifts observed in the molecular energy spectrum (MES) and density of state (DOS) profiles. The reduction in the HOMO-LUMO gap suggests enhanced physicochemical and electrochemical sensitivity of the synthesized composites to external stimuli, making them promising candidates for sensing and optoelectronic devices.