Surface morphology and photoluminescence properties of ZnO thin films obtained by PLD
(1. Key Lab of Automobile Materials, Ministry of Education,
College of Materials Science and Engineering, Jilin University,
Changchun 130025, China;
2. College of Materials Engineering, Southwest Jiaotong University,
Chengdu 610031, China)
College of Materials Science and Engineering, Jilin University,
Changchun 130025, China;
2. College of Materials Engineering, Southwest Jiaotong University,
Chengdu 610031, China)
Abstract: ZnO thin films on Si(111) substrate were deposited by laser ablation of Zn target in oxygen reactive atmosphere, Nd-YAG laser with wavelength of 1064nm was used as laser source. XRD and FESEM microscopy were applied to characterize the structure and surface morphology of the deposited ZnO films. The optical properties of the ZnO thin films were characterized by photoluminescence. The UV and deep level (yellow-green) light were observed from the films. The UV light is the intrinsic property and deep level light is attributed to the existence of antisite defects (OZn). The intensity of UV and deep level light depends strongly on the surface morphology and is explained by the surface roughness of ZnO film. A strongly UV emission can be obtained from ZnO film with surface roughness in nanometer range.
Key words: ZnO; pulsed laser deposition; UV photoluminescence; film