Growth and Photoluminescence of ZnO and Zn1-xMgxO Nanorods by High-pressure Pusled Laser Deposition

The influence of the experimental parameters such as temperature, target, and thickness of catalyst layer on the growth of nanorods were systemically studied by a newly designed and home-built high-pressure pulsed laser deposition Zn1-xMgxO (PLD). The growth mechanism and photoluminescence properties of ZnO and Zn1-xMgxO nanorods were also investigated. It was found that c-orientated ZnO nanorod arrays grown on silicon substrate were obtained when the growth temperature was 925 C and the thickness of gold catalyst layer was 2 nm. It was also proved that growth temperature and catalyst layer thickness were both crucial for the diameter and growth density of ZnO nanorods. A combination of vapor-liquid-solid (VLS) and vapor-solid (VS) mechanism was proposed to describe the growth of ZnO nanorods by high-pressure PLD. Zn1-xMgxO nanorods and nanobelts with random orientation were grown by doping the ZnO target with MgO. The bandgap of ZnO was effectively expanded together with defect-related levels formation in the forbidden gap, which also induced enhancement of visible peak emission.