Preparation and characterization of nanocrystalline tin oxide thin films deposited at room temperature

SnO2 nanocrystalline thin films were deposited onto glass substrates by a Modified Successive Ionic Layer Adsorption and Reaction technique at room temperature. The deposition parameters were optimized and the films were annealed in oxygen atmosphere (500 °C, 1 h). The obtained (as-deposited and annealed) thin films were characterized for structural, optical and electrical properties. X-ray diffraction patterns revealed that the films were either nanocrystalline and/or amorphous in nature with cassiterite tetragonal structure. Atomic force microscopy studies showed uniform grain distribution with average grain size found to be increased from 86 nm for as-deposited to 94 nm for the annealed samples. Optical band gap (3.62 eV) for as-deposited samples was decreased to 3.51 eV after annealing. A decrease in photoluminescence intensity was observed after annealing. Schottky junction of SnO2 with silver has been made and barrier height (0.51 eV) was determined using current–voltage characteristics. The junction gave good response on illuminating it with 150 mW cm− 2 light intensity.