Effect of thermal treatment on the optoelectronic characteristics of indium tin oxide coatings

Subject of study. The effect of annealing in a nitrogen atmosphere on the optoelectronic characteristics and surface morphology of indium tin oxide (ITO) thin films is studied. Aim of study. The preparation conditions for ITO thin films with tailored optoelectronic and morphological characteristics are optimized by varying the film thickness and via thermal treatment at 200°C in a nitrogen atmosphere. Method. The optical properties of the films, including light transmittance and haze, are investigated by spectrophotometry. The electrical characteristics are measured using the four-probe method to determine the sheet resistance. Atomic force microscopy is used to examine the surface morphology and thus measure the surface roughness and determine the grain size via autocorrelation analysis. Main results. Thermal treatment in a nitrogen atmosphere improves the optoelectronic characteristics of ITO coatings. The calculated figure of merit confirms that the light transmittance increases, whereas the surface resistance decreases. Morphological analysis reveals that upon increasing the film thickness, the grain size decreases, whereas the grain density increases owing to the activation of diffusion and nucleation processes. Practical significance. The obtained results confirm the effectiveness of using thermal treatment in a nitrogen atmosphere as a viable method for improving the characteristics of ITO coatings, thereby expanding their applicability in optoelectronic devices requiring high transparency, low resistance, and structural stability.