Influence of the substrate temperature on the optical and electrical properties of Ga-doped ZnO thin films fabricated by pulsed laser deposition

Ga-doped (5 wt%) zinc oxide (GZO) thin films were fabricated on corning 1737 substrates at a fixed oxygen pressure of 200 mTorr at various substrate temperatures (100–300 °C) by using pulsed laser deposition (PLD) in order to investigate the microstructure, optical, and electrical properties of the GZO thin films. It was observed that all the thin films exhibit c-axis orientation and exhibit only a (002) diffraction peak. The GZO thin film, which was fabricated at 200 mTorr and 300 °C, showed the highest (002) orientation, and the full width at half maximum (FWHM) of the (002) diffraction peak was 0.38°. The position of the XRD peak shifted to a higher angle with increase in the substrate temperature. The optical transmittance in the visible region was greater than 85%. The Burstein-Moss effect, which causes a shift toward a high photon energy level, was observed. The electrical property indicated that the highest carrier concentration (2.33 × 1021 cm−3) and the lowest resistivity (3.72 × 10−4 Ωcm) were obtained in the GZO thin film fabricated at 200 mTorr and 300 °C.