Dy~(3+)和La~(3+)掺杂ZnO薄膜的特点及其气敏传感特性

Abstract

采用真空蒸发的方法制备了掺杂原子比为3%、5%和9%的lA掺杂和dy掺杂的znO薄膜.用扫描电子显微镜(SEM)、X射线衍射(Xrd)谱和X射线光电子能谱(XPS)表征了所制得的znO薄膜的特性.发现所有薄膜都沿C轴取向优先生长.在对znO薄膜气敏特性的测量中,在低温条件下掺杂znO薄膜的电阻比非掺杂znO薄膜的小,且对乙醇和丙酮的灵敏度显著增强,且其中dy掺杂的znO薄膜的气敏特性较lA掺杂的znO薄膜为高.而空气中暴露9个月后的薄膜的气敏特性表明掺杂znO薄膜具有很好的稳定性.同时讨论了气敏传感机制和掺杂行为对薄膜灵敏度的影响.

La and Dy-doped ZnO thin films were prepared via vacuum evaporation method at mass fraction of 3%,5% and 9% dopi ng.The obtained films were characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS).The results indicated that all films showed a preferred C-axis growth orientation.Compared with undoped ZnO thin films,the doped films exhibited a downshift of resistance at a low temperature and remarkable increase of sensitivity to ethanol and acetone vapour,and the sensitivity of Dy-doped ZnO thin films were higher than the sensitivity of La-doped ZnO thin films.The films were then exposed bare in air for 9 months and the sensitivity was remeasured.All the films remained the sensitivity at a high level which indicated an excellent stability.The sensing mechanism and the effect of doping behaviour were also discussed.