Influence of Spray Solution Quantity on Microstructural and Optical Properties of In2O3 Thin Films Prepared by Spray Pyrolysis

Abstract

AbstractHighly textured indium oxide (In2O3) thin films are produced by chemical spray pyrolysis method onto glass substrates. The impact of film thickness on the structural, morphological, and optoelectronic properties of In2O3 thin films are investigated. The effect of film thickness on microstructural properties like grain size, lattice constants, dislocation density, and strain of the films are reported. X‐Ray diffraction study reveals that the thin films have a cubic structure with favored (222) plane. The morphological study shows the spherical and uninterrupted distribution of grains. The typical transmittance of the In2O3 thin films, measured in the 300–1100 nm wavelength. The optical properties show that direct band gap value improved from 3.35–3.52 eV with film thickness. The best results are shown with 352 nm film thickness which has direct band gap of 3.49 eV, minimum sheet resistance of 80 Ω/□, lowest resistivity of 4 × 10−3 Ω. cm, maximum carrier concentration 6.1 × 1020 cm−3, mobility 29.55 cm2 V−1 s−1 and highest figure of merit is achieved (12.110−2 □/Ω). The results exhibited the 60 mL spray solution quantity of In2O3 films is suitable for device application.