Studies On The ZnO, TiO2Single Crystals Modification By Ion Implantation, And The Photoelectric Properties Of Li0.2Zn0.8O/Al0.15Zn0.85O Bilayer

ZnO and TiO2, as two kinds of metal oxide, play an important role in the field of optoelectronic and photocatalysis respectively. ZnO has a direct wide band gap(3.37eV) and a large exciton bonding energy (60meV). It have broad application prospects, such as diluted magnetic semiconductor, ultraviolet optoelectronic devices, piezoelectric devices, gas-sensing devices etc. Due to photoinduced properties, TiO2has extensive uses in environment-protection and energy-conversion field, such as photocatalytic degradation of pollutants, self-clean coating, hydregon-production through photocatalytic water splitting, and fabrication of solar energy cells. In this paper, the different metal ions doped ZnO and TiO2samples were prepared by using ion implantation method and pulsed laser deposition technique. The following is the main content of the study and results:1. Co ions implanted ZnO crystal and Cu ions implanted ZnO crystal system:(1) We studied the influence of implantation dose on the photoluminescence of the Co-implanted ZnO and found that green luminescence centre shift from518nm to530nm with the increase of implantation doses.(2) The VSM measurements show that all Co ions doped ZnO crystal samples is ferromagnetic at room temperature, and the saturation magnetization increased with the increase of implantation dose from5×1014ions.cm-2to1×1016ions.cm-2, but it began to decreased when the implantation dose to5×1016ions.cm-2.(3) We also observed the hysteresis loops of Cu ions doped ZnO crystal samples, It means nonmagnetic metal Cu ions doped ZnO have ferromagnetism.2. Co ions implanted TiO2crystal system:(1) UV-Vis measurement shows that the absorbance of all doped samples in visible light is enhanced, and the band gap structure was damage when the implanted dose to1×1017ions/cm2.(2)Optical band gap increased gradually with the increase of the implanted dose from5×1015ions/cm2to5×1016ions/cm2.3. Al ions doped ZnO film and Li ions doped ZnO film system:(1) Both Li0.2Zn0.8O thin film and Li0.2Zn0.8O/Al0.15Zn0.85O multilayers have response to UV illumination in air at room temperature, and show PR effect with the value of～340%and～8600%. (2) Because the PR effect of bilayers of Li0.2Zn0.8O/Al0.15Zn0.85O is much lager than Li0.2Zn0.8O thin film, so it is promising for UV photodetection applications. According to the analysis it concluded that the enhanced PR effect in the Li0.2Zn0.8O/Al0.15Zn0.85O multilayers is probably due to the interface of those two layer where a p-n junction is formed.