退火温度对WO_3薄膜结构及气敏性能的影响

Effect of annealing temperature on structure and gas-sensing properties of WO_3 thin films

采用直流磁控溅射法制备了WO3薄膜，并在350—550℃时对薄膜进行退火处理，研究了退火温度对薄膜结构及气敏性能的影响。结果表明：退火前及350℃退火后的薄膜为非晶态，450℃和550℃退火后的薄膜为WO3-x型晶态；随退火温度的提高，薄膜厚度增加，晶粒度增大。550℃退火后薄膜的厚度，较450℃退火后薄膜厚30nm，晶粒度相差8nm；450℃和550℃退火后的薄膜，在150℃时对体积分数为0．05％的NO2的灵敏度接近于22。

WO3 thin films were deposited onto glass substrates by DC magnetron sputtering technology and then it was annealed at 350- 550℃. Effects of annealing temperature on the structure and gas-sensing properties of the thin films were studied. The results show that as-deposited thin films and thin films annealed at 350 ℃ are amorphous, the thin films annealed at 450℃ and 550℃ are WO3_x crystaIs. As the annealing temperature increases, the crystallite and the thin film thickness increase simultaneously. The thickness of thin films annealed at 550℃ is thicker than that of the thin films annealed at 450℃ by 30 nm and the crystallite is bigger by 8 nm. The sensitivity of thin films annealed at 450 ℃ and 550 ℃ to 0.05% （volume fraction） NO2 is about 22 at working temperature of 150℃.