The Main Role of Thermal Annealing in Controlling the Structural and Optical Properties of ITO Thin Film Layer

TL;DR

This study investigates how thermal annealing affects the structural, optical, and electrical properties of indium tin oxide (ITO) thin films, revealing temperature-dependent changes in energy gaps, exciton energies, and optical behaviors.

Contribution

It provides new insights into the influence of annealing temperature on ITO thin films' properties, combining structural, optical, and electrical analyses.

Findings

Orbital transition energies increase with annealing temperature.

Urbach energies behave differently with temperature.

Surface resistance and optical properties vary with annealing.

Abstract

Here we report on studying the electronic and optical material properties of the technologically-relevant material indium tin oxide (ITO) as a function of thermal annealing. In this work, ITO powder has been prepared utilizing solid-state reaction methods. An electron beam gun technology has been used to prepare a ITO film (325 nm). The ITO window layer has been investigated at various temperatures. The effects of absolute temperature on the structural, optical, and electrical properties of the prepared ITO thin film layer are investigated. The energy band type corresponding to the orbital transitions has been determined, and the energies of the orbital transitions have been calculated in the Tauc region, HOMO/LUMO gap, and charge transfer gap. In additions, the exciton and Urbach energies have been computed. It has been found that these energies increase with increasing the annealing temperature, except for Urbach's energies which behave differently. Thin-film quality coefficient, surface resistance, and thermal emission in addition to the angle of refraction as a function of wavelength, have been determined.