Effect of deposition temperature on the properties of nitrogen-doped AZO thin films grown on glass by rf reactive magnetron sputtering

Nitrogen-doped aluminum zinc oxide (NAZO) thin films were deposited on glass substrates at various deposition temperatures by rf reactive magnetron sputtering. The NAZO film deposited at 400 °C shows a strongly c-axis preferred orientation and n-type conduction with a resistivity of 2.1 × 10−2 Ω cm, Hall mobility of 7.7 cm2 V−1 s−1, and electron concentration of 3.8 × 1019 cm−3. The optimum crystallographic structure occurs at a deposition temperature of 400 °C, where a considerable crystallinity enhancement of the films is observed. The band gap energies of the NAZO films, obtained by using Tauc model and parabolic bands, are found to significantly depend on the deposition temperature, along with the band gap narrowing at higher deposition temperature due to renormalization effects.