A study of the optical band gap of zinc phthalocyanine nanoparticles using UV–Vis spectroscopy and DFT function

Abstract

In the present work, we used the ultraviolet–Visible (UV–Vis) spectroscopy technique to find the optical band gap of zinc phthalocyanine nanoparticles (ZnPc-NP) experimentally. Moreover, we used a time-dependent density functional theory (TDDFT) to simulate the UV–Vis absorption spectrum of ZnPc molecule in gas and solution phases. The ZnPc-NP absorption spectrum shows a shift toward higher energies compared to the bulk ZnPc. The simulated UV–Vis and the experimental nanoparticle’s spectrum were found to have a good agreement. The ZnPc energy band gap from the DFT calculations shows how it’s possible to get wider range of energy band gap for the ZnPc. The ZnPc-NP’s size and shape were examined using the transmission electron microscope (TEM).