Effects of Sputtering Power and Gamma Radiation Dose on the Optical and Electrical Properties of ITO Films

ITO films were deposited on glass substrates using DC magnetron sputtering at different sputtering powers of 10 and 20 W. All films were irradiated with gamma radiation at doses ranging from 0 to 150 kGy. XRD results showed that ITO films at 10 W sputtering power exhibited decreased crystallinity with increasing gamma doses, while films at 20 W showed higher crystallinity at 50 kGy, which then decreased with further irradiation. The optical transmittance and energy band gap decreased with increasing doses, indicating structural changes due to defect formation. The electrical resistivity of the ITO film increased with the irradiated dose for a sputtering power of 10 and 20 W due to the increased defect formation in the structure. Even though the sputtering power condition was 20 W, after irradiation with a dose of 50 kGy, the ITO film exhibited higher crystallinity but had a predominant change in the (222) plane instead of the (400) plane. This study revealed the important role of deposition parameters and gamma irradiation in controlling structural, optical, and electrical properties of ITO films. The reduced resulting energy band gap is linked to increased resistance in ITO films after exposure to gamma radiation, with defect formation.