Fine-tuning SnO2 films: Unleashing their potential through deposition temperature optimization by ultrasonic spray pyrolysis

Abstract

In this study, the optimization of the deposition temperature, which directly affects the crystallinity, morphology, and electrical conductivity of SnO2 films deposited onto Corning Eagle XG glass substrates using the ultrasonic spray pyrolysis technique, was investigated to tailor their physical properties for various applications. Structural analyses revealed that the films had a tetragonal rutile structure, and while films deposited at lower temperatures exhibited a higher prevalence of (200) oriented planes, yet this decreased with an increase in deposition temperature. Morphological analyses showed that the films consisted of grains with octahedral shapes, and films deposited at lower temperatures were found to be more compact. The films had bandgap energy ranges between 3.96 eV and 4.02 eV. Hall effect measurements revealed that not only the carrier concentration decreased from 4.52 × 1019 cm−3 to 0.80 × 1019 cm−3, but the mobility also decreased from 23.32 cm2/Vs to 12.85 cm2/Vs. Among all the films, it was noted that the films deposited at 350 °C had the highest figure of merit which is 12.3 × 10−4 Ω−1. It can be concluded that the changes underlying these variations are associated with structural and morphological changes depending on the substrate temperature. Also, significant results have been attained in applications where precise control over crystal structure and surface morphology is crucial.