脉冲激光沉积ZnO薄膜的微结构及发光性能

Surface Morphology and Photoluminescence Properties of ZnO Films Deposited with PLD

用波长为1 064 nm的Nd-YAG激光器,在氧的活性气氛中,通过激光烧蚀Zn靶在S i(111)衬底上获得ZnO薄膜.用电子显微镜(XRD和FESEM)表征ZnO薄膜的结构和表面形貌,用光致发光谱表征光学性质.实验中观察到紫外光发射和深能级的黄绿光发射.紫外光发射是ZnO薄膜的固有性质,深能级光发射是由于存在氧反位缺陷(OZn).紫外光发射和深能级光发射的强度依赖于薄膜的表面粗糙度.表面粗糙度在nm级范围内的ZnO薄膜可以获得高强度的紫外光.

ZnO films were deposited on a Si （ 111 ） substrate by laser ablation of a Zn target in oxygen reactive atmosphere. Nd-YAG laser with wavelength of 1 064 nm was used as the laser source. The structure and surface morphology of the deposited ZnO films were characterized with XRD （X ray defraction） and FESEM （field emission scanning electron microscopy） , and the optical properties of the films were characterized with photoluminescence. The UV （ultraviolet） and deep level （ yellow- green） radiations were observed from the films. The UV radiation is the intrinsic property of ZnO film, and the deep level radiation is due to the existence of oxygen antisite defects （OZn）. The intensity of UV and deep level radiations depend strongly on surface morphology and surface roughness of ZnO films. A strongly UV emission is obtainable from ZnO film with surface roughness in nanometer range.