中国物理B ›› 2011, Vol. 20 ›› Issue (3): 36103-036103.doi: 10.1088/1674-1056/20/3/036103
• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇 下一篇
袁华军, 陈亚琦, 余芳, 彭跃华, 何熊武, 赵丁, 唐东升
Yuan Hua-Jun(袁华军)†, Chen Ya-Qi(陈亚琦)†, Yu Fang(余芳), Peng Yue-Hua(彭跃华), He Xiong-Wu(何熊武), Zhao Ding(赵丁), and Tang Dong-Sheng(唐东升)‡
摘要: This paper reports that highly purified hexagonal WO3 nanowires are synthesized by a simple hydrothermal method. The as-synthesized WO3 nanowires are investigated in detail by ultraviolet--visible--near infrared spectroscopy and electrical transport measurements under different conditions. It finds that the optical band gap and the diffuse reflection coefficient in the wavelength region above 450 nm of WO3 nanowires decrease observably upon exposure to ultraviolet light or NH3 gas. It is also found that there are electrons being trapped or released in individual WO3 nanowires when scanning bias voltage in different directions upon exposure to ultraviolet and NH3 gas. The experimental results suggest that the chromic properties might be attributed to the injection/extraction of hydrogen ions induced by ultraviolet light irradiation in air or creation/annihilation of oxygen vacancies induced by NH3 gas exposure, which serve as colour centres and trap electrons as polarons. The experimental results also suggest that the hexagonal WO3 nanowires will be a good candidate for sensing reduced gas such as NH3.
中图分类号: (Structure of nanowires and nanorods (long, free or loosely attached, quantum wires and quantum rods, but not gate-isolated embedded quantum wires))