GaN nanorods have successfully been synthesized on Si(111) substrates via ammoniating ZnO/Ga2O3 films at 950°C. Ga2O3 thin films and ZnO middle layers were deposited in turn on Si(111) substrates by r.f. magnetron sputtering system. ZnO volatilized at 950°C in the ammonia ambience and Ga2O3 reacted to NH3 to fabricate GaN nanorods in the later ammoniating process. The volatilization of ZnO layers played an important role in the fabrication. The structure and composition of the GaN nanorods were studied by X-ray diffraction (XRD) and Fourier transform infrared spectropho-tometer (FTIR). The morphology of GaN nanorods was investigated using scanning electron microscopy (SEM) and trans-mission electronic microscope (TEM). The analyses of measured results revealed that GaN nanorods with hexagonal wurtz-ite structure were prepared by this method.
ZnO thin films are deposited on n-Si(111) substrates by pulsed laser deposition(PLD) system. Then the samples are annealed at different temperatures in air ambient and their properties are investigated particularly as a function of annealing temperature. The microstructure, morphology and optical properties of the as-grown ZnO films are studied by X-ray diffraction(XRD), atomic force microscope(AFM), Fourier transform infrared spectroscopy(FTIR) and photoluminescence(PL) spectra. The results show that the as-grown ZnO films have a hexagonal wurtzite structure with a preferred c-axis orientation. Moreover, the diameters of the ZnO crystallites become larger and the crystal quality of the ZnO films is improved with the increase of annealing temperature.
ZHUANG Hui-zhao XUE Shou-bin XUE Cheng-shan HU Li-jun LI Bao-li ZHANG Shi-ying
The behavior of Ti based on Si(111) in oxygen under high temperatures(700 ℃, 800 ℃, 900 ℃, 1 000 ℃ and 1 100 ℃) is reported. X-ray diffraction(XRD) and Fourier transform infrared spectroscopy(FTIR) are used to analyze the structure and composition of the samples annealing at different temperatures in oxygen ambience. It is found that raising temperature is helpful to the formation of both TiSi2 and TiO2 and helpful to the diffusion of Ti to Si substrate.
ZnO thin films were deposited on n-Si (111) at various substrate temperatures by pulsed laser deposition (PLD). X-ray diffraction (XRD), photoluminescence (PL), Fourier transform infrared spectrophotometer (FTIR), and scanning electron microscopy (SEM) were used to analyze the structure, morphology, and optical property of the ZnO thin films. An optimal crystallized ZnO thin film was obtained at the substrate temperature of 600°C. A blue shift was found in PL spectra due to size confinement effect as the grain sizes decreased. The surfaces of the ZnO thin films were more planar and com- pact as the substrate temperature increased.
HE Jianting ZHUANG Huizhao XUE Chengshan WANG Shuyun HU Lijun XUE Shoubin
