Structural, electronic, and optical properties of Zn-doped V₂O₅ thin films

Abstract

Abstract V 2 O 5 shows a diverse range of applications due to its remarkable electronic and optical properties. This research is designed to tune the electronic and optical properties of V 2 O 5 through modification in the energy band profile by varying Zn doping concentration. Density functional theory (DFT) calculations were used to investigate the Density of States (DOS) spectra for pure V 2 O 5 , exhibiting the prominent contribution of V- d and O- p orbitals, representing the p-d hybridized orbitals along with additional Zn- d orbital contribution in Zn-doped compositions. The effects of doping on the structural, morphological, elemental, and optical properties of the developed thin films were investigated employing x-ray diffraction (XRD), scanning electron microscope (SEM), x-ray dispersive spectroscopy (EDX), and spectroscopic ellipsometry (SE), respectively. x-ray diffraction analysis revealed the orthorhombic crystal structure in thin films. Surface morphology depicts the uniformly distributed compact rod-like features. The experimentally calculated band gap was found to decrease with Zn doping from 2.77 eV for pure V 2 O 5 to 2.45 eV for maximum doping content. A significant variation is recorded in optical parameters like the increase in absorption coefficient and optical conductivity, which makes these more favorable for optoelectronic devices, particularly focusing on photovoltaics.