First-principles calculations to investigate the influence of porphyrin substitution on the structural, electronic and optical properties of graphene oxide

Abstract

The following article aims to investigate the influence of porphyrin (PP) on the crystallinity, electronic structure, and optical properties of graphene oxide (GO), using the density functional theory (DFT). Theoretical calculation indicates that porphyrin substitution brings about significant distortion in the GO sheet. The substitution of porphyrin on the graphene oxide layer (GO-PP), leads to decrease the bandgap of the GO material. After substitution, the absorption coefficient decreases in the UV domain and increases in the visible range. Thus, the observed redshift in absorption peaks upon porphyrin substitution was attributed to the assembly that consists of J-aggregates. In this work, we explore the substitution effect of PP chain on the GO sheet as a window layer, over the power conversion efficiency of solar cells. The substitution of PP chain on the GO sheet improves the degree of power conversion efficiency of solar cells. Further comparison indicates that calculations are consistent with experimental observation, which indicates that DFT calculation at CASTEP code level gives good results of porphyrin substitution on the graphene oxide layer.