Towards significant enhancement of structural and optoelectronic properties of porphyrin palladium(II) complex: A theoretical and experimental analysis

Abstract

Abstract In the present investigation, the nanostructure of porphyrin palladium(II) complex thin films was fabricated by low-cost conventional thermal analysis. The experimental and simulation investigations were used for the analysis of the structure and the unique optical characteristics for optoelectronic applications. The simulation processes using TD-DFT/ B3LYP were implemented to extract the distinguished geometry optimizations and other related parameters. The quantum theory of atoms in molecules (QTAIM) was additionally applied for the studied complexes to evaluate their peculiar electronic features. An indexation of XRD was performed to give a full identification of the crystal structure and supported by the results of transmission electron microscopy images. The investigation of the surface morphology and its quality for the optical applications was established using the atomic force microscopy, AFM supported surface topography mapping images. The optical properties confirm two main direct transitions with determined band gaps of 2.31 and 2.98 eV. The experimental optical gap was comparable with those theoretically extracted using DFT. The characteristics of the current density-voltage measurements verified rectification in the dark and under different values of illuminations. The device showed remarkable rectification characteristics with good responsitivity under illumination conditions. The maximum external quantum efficiency of 9.8% was obtained and compared to other organic-based devices.