Structural, optical and sensitivity study of optimized indium oxide thin film for gamma sensing applications

Abstract

Measurement of radiation dose has the utmost importance in the field of medicine and research. This work aims the estimation of the sensitivity of Indium oxide thin film for dosimetry application. Indium oxide thin film prepared using spray pyrolysis on a glass substrate with an optimized concentration of 0.1 M and temperature of 450 0C was exposed to different gamma radiation doses using Co- 60 as the radiation source. The impact of irradiation on the structural properties of the film was investigated by XRD and a higher crystallite size was obtained for a dose of 200 Gy. The phase purity and vibrational modes of the irradiated films were investigated using Raman spectra. The optical characterization of the irradiated film shows negligible variation in bandgap with irradiation. The optical parameters like refractive index and extinction coefficient are also extracted from optical data. The reduction in the intensity of PL peaks after irradiation was attributed to the annihilation of gamma-induced defect levels. The thermoluminescence curve indicates the suitability of In2O3 as dosimeters. XPS analysis also supports the annihilation of defects at 200 Gy. The electrical measurement was used to find the sensitivity of the film at different applied voltages and it lies in the range of 101 − 380 mA/cm2/Gy. The fact that irradiated material undergoes a change in physical properties due to the influence of gamma-ray can be utilized for gamma dosimetry applications. The changes induced by gamma-ray in structural, optical and electrical properties have been investigated in detail.