Effect of tantalum doping on the microstructure and photoelectrical properties of transparent conductive zinc oxide films

ZnO thin films with varying Ta concentrations were fabricated through magnetron sputtering. The crystallinity and surface morphology of the ZnO films are significantly influenced by the incorporation of Ta, as evidenced by the X-ray diffraction and scanning electron microscopy results. The lattice constants, as determined by X-ray diffraction, contradict the disparity in Ta and Zn ion radii, which is attributed to the impact of interstitial defects. This inconsistency introduces variations in carrier concentration in this experiment compared with prior studies. Subsequent exploration of the luminescent characteristics and emission mechanism of defect levels in Ta-doped ZnO films was conducted through photoluminescence. Furthermore, the factors influencing the bandgap are discussed.