Spray pyrolysis derived ZnMgO:In thin films: Investigation of the structural, optical and electrical properties

Zn1−xMgxO:In films were deposited on quartz substrates via ultrasonic spray pyrolysis (USP). By tuning the molar ratio of Zn and Mg sources, the tunable band gap in ZnMgO:In films were realized. The obtained films exhibited wurtzite crystal structure with a preferential c-axis orientation. Larger grain size was obtained with increasing the Mg introduction. Photoluminescence (PL) indicated that the peaks of near-band-edge (NBE) emission appeared as a blue-shift from 378 nm to 370 nm, labeled as x value increase from 0 to 0.15. Optical band gap (Eg) calculated from the absorption edge further confirmed the blue-shift phenomenon due to the Mg substitution for Zn lattice sites. The average transmittance was about 90% in the visible wavelength region (400-800 nm). The increasing resistivity from 6.70 × 10−3 Ω cm to 2.14 × 10−2 Ω cm and decreasing mobility from 24.7 cm2 V−1 S−1 to 6.46 cm2 V−1 S−1 were observed.