Ga掺杂纳米TiO2薄膜的制备及其光电特性

利用射频磁控溅射法在玻璃衬底上制备了Ga掺杂的TiO₂薄膜，并在真空中于550 ℃下进行了2 h的退火处理。采用XRD、SEM、UV-Vis和PL光谱对薄膜进行了表征。XRD结果提示，在溅射功率为200 W，室温下制备的TiO₂薄膜具有混晶结构，且退火后的晶粒有长大的趋势。SEM分析表明，掺Ga薄膜的颗粒分布得较为均匀并存在尺寸变小的趋势，且出现有利于提高光催化性能的岛状结构，其平均颗粒尺寸为50 nm。UV-Vis透过谱指出，掺Ga后的TiO₂薄膜吸收边发生了明显红移，且退火后进一步红移了10~50 nm。通过接触角的测量与计算可知，550 ℃退火2 h后的薄膜具有良好的亲水性。光催化降解结果表明：样品具有较强的光催化能力。当用低功率(15 W)紫外灯照射8 h后，Ga掺杂的纳米TiO₂薄膜样品对亚甲基蓝溶液的降解率最高可达到71.8%。

Ga-Doped Nano-TiO2 Thin Films: Preparation, Optical and Electrical Properties

The gallium-doped TiO_2 thin films were deposited on glass substrate by Radio Frequency(RF) magnetron sputtering, and annealing treated in vacuum for 2 h at 550℃. The films were characterized using XRD, SEM, UV-Vis transmission spectraoscopy. XRD results show that the TiO_2 thin films change to mixed crystal with sputtering power of 200 W at room temperature, and the gains have grown up trend after annealing. SEM results reveal that Ga-doped thin films have a more uniform and smaller particle size distribution with an average size of 30 nm. The surface morphology is land-like. UV-Vis transmission spectra show that the absorption edge of the Ga-doped thin films occurs obviously red-shifted, and even a red-shift of 10～50 nm is found after annealing. The films have good hydrophilicity as evidenced by contact angle measurement and calculation. The samples exibit good photocatalytic activity as shown by the degradation rate of 71.8% for methylene blue solution after 8 h irradiation under low power UV lamp(15 W).