Investigation on dispersion parameters of Molybdenum Oxide thin films via Wemple–DiDomenico (WDD) single oscillator model

Abstract

In this paper, the dispersion parameters of Molybdenum Oxide thin films viz: oscillator energy, dispersion energy, transition moments, static refractive index, oscillator strength, and oscillator wavelength are estimated via Wemple–DiDomenico (WDD) single oscillator model. The crystal structural, surface morphological, and optical transmission properties of Molybdenum Oxide thin films are also investigated so as to extract vital in-put parameters for WDD model. The X-ray Diffraction and Fourier Transform of Infrared analysis confirm that the film fabricated at substrate temperature ~ 300 °C under goes a successful dual phase transformation from amorphous to α- and β-MoO3 crystalline phase. Static refractive indices of the films are found to be vary from ~ 1.84 to 2.04 with the increase of substrate temperature during the thin film growth process via thermal evaporation technique. Moreover, the optical constants viz: film density, porosity, absorption coefficient, optical band gap, Urbach energy, steepness parameter, and strength of electron–phonon interaction are also studied as a function of substrate temperature. This is to establish a correlation between optical constants and dispersion parameters in the present paper.