Structural and optoelectrical properties of Ga-doped ZnO semiconductor thin films grown by magnetron sputtering.

Transparent conductive gallium-doped zinc oxide (Ga-doped ZnO) films were prepared on glass substrate by magnetron sputtering. The influence of substrate temperature on structural, optoelectrical and surface properties of the films were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), spectrophotometer, four-point probe and goniometry, respectively. Experimental results show that all the films are found to be oriented along the c-axis. The grain size and optical transmittance of the films increase with increasing substrate temperature. The average transmittance in the visible wavelength range is above 83% for all the samples. It is observed that the optoelectrical property is correlated with the film structure. The Ga-doped ZnO film grown at the substrate temperature of 400 °C has the highest figure of merit of 1.25 × 10−2 Ω−1, the lowest resistivity of 1.56 × 10−3 Ω·cm and the highest surface energy of 32.3 mJ/m2. [ABSTRACT FROM AUTHOR]