Abstract
This study investigates the influence of cation (Cu2+) and anion (Br-) doping on the physical properties of indium oxide thin films to evaluate their potential for transparent conductive oxide (TCO) applications. Undoped, Cu2+-doped, and Br--doped indium oxide thin films were grown on glass substrates (sample size: 1.25 cm × 1 cm) using the ultrasonic spray pyrolysis technique, and their structural, optical, and electrical characteristics were investigated using X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), and the four-point probe technique. XRD revealed that Cu2+ doping reduced the average crystallite size, whereas Br- doping had little effect. Optical characterization indicated that Br doping enhanced their transmittance to 85%, with a slight widening of the bandgap from 3.69 to 3.73 eV, while Cu2+ narrowed it to 3.66 eV. Electrical measurements revealed that Br- incorporation reduced resistivity and yielded a superior figure of merit. The study concludes that bromine doping significantly improves the optoelectronic performance of In2O3 films compared to copper doping, suggesting that Br-doped films are promising candidates for high-performance transparent conductive electrode applications.