Micro-textured milky ZnO:Ga thin films fabricated by pulsed laser deposition using second-harmonic-generation of Nd:YAG laser

Approximately 800-nm-thick ZnO films doped with 4 wt% Ga2O3 (GZO films) have been deposited on glass and quartz substrates by a pulsed laser deposition method using Second-Harmonic-Genreation (SHG) of Nd:YAG laser (lambda = 532 nm). In all experiments, a repetition rate of 10 Hz, energy densities of 0.1-2.5 J/cm(2), and irradiation times of 2-3 h were used. Scanning Electron Microscopy (SEM) observations of the film surface revealed that there were micro-textured structures (0.5-1 mu m in diameter), surrounded by small rugged and irregular structures (250-400 nm in size). It was recognized from XRD spectra that a strong peak of (103) planes reflected from the micro-textured milky surfaces is dominant. A haze ratio of 46.6% was obtained at a wavelength of 550 nm for approximately 800-nm-thick GZO (4 wt%) films grown at a substrate temperature of 300 degrees C in oxygen with a flow rate of 3 seem, The lowest resistivity of 2.33 x 10(-4) Omega cm and the lowest sheet resistance of 2.72 Omega/sq were obtained for these GZO (4 wt%) films.