Real-time measurement of laser induced photoconductivity in sol-gel derived Al doped ZnO thin films

TL;DR

This study investigates the real-time photoconductivity response of Al-doped ZnO thin films prepared via sol-gel, revealing how laser irradiation influences their electrical and structural properties, with potential implications for optoelectronic applications.

Contribution

It introduces a novel real-time measurement approach for laser-induced photoconductivity in sol-gel derived AZO thin films, linking structural, optical, and electrical changes during irradiation.

Findings

Photoconductivity can be transient or persistent depending on laser energy.

Crystalline structure develops above 400°C annealing temperature.

Laser irradiation significantly alters surface morphology and optical properties.

Abstract

In this paper Al doped ZnO (AZO) thin films with 0, 3, 6 and 12 at. % Al concentration were prepared by sol-gel method on glass substrates. The deposited films were annealed at different temperatures of 300, 350, 400, 450 and 500 {\deg}C for 1 h in air. X-ray diffraction (XRD) showed wurtzite crystalline structure for the films annealed above 400 {\deg}C. The films were subsequently irradiated by beams of excimer (KrF, {\lambda}=248 nm) laser. The evolution of crystal structure, surface morphology and optical properties were studied using XRD, filed emission scanning electron microscope (FE-SEM) and UV-Vis spectrophotometer, respectively. Real-time measurement of electrical conductivity during laser irradiation showed a transient or persistent photoconductivity effect. The effect of laser energy on this photoconductivity was also investigated. Based on the observed photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS), the observed photoconductivity effect was described.