The structural and optical behaviors of K-doped ZnO/Al_(2)O_(3)(0001) films

摘要

K-doped ZnO films were prepared on Al_(2)O_(3)(0001) substrates by solution deposition. For the prepared thin films of Zn_(1-x)K_(x)O (x=0.002, 0.01, 0.02, 0.05, 0.1), we carried out x-ray diffraction, transmittance spectroscopy, photoluminescence, Hall measurement and x-ray photoemission spectroscopy study, and found that properties like the crystallinity, optical band gap, carrier concentrations and chemical binding states changed at a K doping concentration of 2 mol %. From these results, we suggest that the doped K in ZnO films processed by the sol-gel method plays a different role at K doping concentrations below 2 mol % and above 2 mol %.