Role of deposition temperature and Sn content on structural, optical & electrical properties of In2O3 thin films

Abstract

High quality indium tin oxide (ITO) thin films (In2−xSnxO3: x = 0, 0.1 and 0.2) have been grown by using pulsed laser deposition technique on quartz substrates. The structural, morphological, optical and electrical investigations of deposited films have been studied as a function of substrate deposition temperatures and the Sn compositions. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) patterns affirm that each film is polycrystalline in nature with cubic bixbyite single phase structure which preferentially oriented along (222) Miller plane. The existence of chemical bonding and functional groups was investigated by FTIR spectroscopy. The TEM micrograph of films (@450°C) for x = 0.1 and x = 0.2 reveal spherical morphology with average particle size 63 nm and 51 nm, respectively. The SEM and AFM images show uniform flower like surface morphology and well-demonstrated nanosized spherical particles, respectively. The widening of the band gap of all the films were exclusively defined by Burstein-Moss shift. The Hall measurement reveals that each film is degenerate with n-type semiconducting nature along with high mobility. Low resistivity (2.024 × 10−4 Ω-cm) and high transparency (92.58%) along with high carrier concentration (8.915 × 1020cm−3) were optimized for x = 0.1 film at 450°C deposition temperature.