Mg-doped ZnO radial spherical structures with nanorods grown on both sides of the spherical shell were successfully prepared via chemical vapor deposition （CVD） of Zn and Mg powders in the absence of a catalyst. The...Mg-doped ZnO radial spherical structures with nanorods grown on both sides of the spherical shell were successfully prepared via chemical vapor deposition （CVD） of Zn and Mg powders in the absence of a catalyst. The structures associated with different growth temperatures （700, 800, and 850°C） were monitored by scanning electron microscopy （SEM）, and the result shows that the length of the nanorods increase progressively with the growth temperature increasing. X-ray diffraction （XRD） shows that the as-obtained samples can be indexed to high crystallinity with wurtzite structure. The growth of the nanostructures mainly depends on the formation of sphere-like Mg-doped Zn droplets before adding oxygen. Photoluminescence （PL） spectra that show a 39 meV blue shift indicates that the band gap becomes large, because Mg substitutes Zn in the lattice.展开更多
1 IntroductionIn the very recent years, low-dimensional nanomaterials have attracted a great interest in nanoscience and nanotechnology due to their exciting application in electronics[1], optoelectronics[2] and mecha...1 IntroductionIn the very recent years, low-dimensional nanomaterials have attracted a great interest in nanoscience and nanotechnology due to their exciting application in electronics[1], optoelectronics[2] and mechanics[3] in nanoscale. Compared to bulk materials,展开更多
ZnS films were successfully grown by metallorganic chemical vapour deposition (MOCVD) at atmospheric pressure on (100) GaAs substrates. The deposition was carried out at a substrate temperature between 280 approximate...ZnS films were successfully grown by metallorganic chemical vapour deposition (MOCVD) at atmospheric pressure on (100) GaAs substrates. The deposition was carried out at a substrate temperature between 280 approximately 550°C with optimisation of reactor design and growth conditions. The gas phase prereaction is effectively restrained. These epilayers exhibit high crystallographic quality and reveal a mirror surface morphology. The peak halfwidths of X-ray diffraction patterns from their (400) faces are within 0.06 approximately 0.09°. The epilayers grown on (111) GaAs, (112¯0) Al2O3 and (100) Si have proven to be single crystalline feature. The optical and electrical characteristics of ZnS epilayers are measured by photoluminescence, cathodeluminescence, and the Van der Pauw method. The results indicate that there are not a large number of deep centers that could be detected both at 77K and at room temperature. A broad CL peak around 2.897eV and 2.672eV was observed only under very strong excitation. Their origin has not been examined. All epilayers present high resistivities up to 1013Ω·cm.展开更多
文摘Mg-doped ZnO radial spherical structures with nanorods grown on both sides of the spherical shell were successfully prepared via chemical vapor deposition （CVD） of Zn and Mg powders in the absence of a catalyst. The structures associated with different growth temperatures （700, 800, and 850°C） were monitored by scanning electron microscopy （SEM）, and the result shows that the length of the nanorods increase progressively with the growth temperature increasing. X-ray diffraction （XRD） shows that the as-obtained samples can be indexed to high crystallinity with wurtzite structure. The growth of the nanostructures mainly depends on the formation of sphere-like Mg-doped Zn droplets before adding oxygen. Photoluminescence （PL） spectra that show a 39 meV blue shift indicates that the band gap becomes large, because Mg substitutes Zn in the lattice.
基金Supported by the National Natural Science Foundation of China(Nos.20827004, 20873050, 20921003, 20973074, 21073072)the "111" Project of China(No.B06009)+1 种基金the Research Fund for the Doctoral Program of Higher Education of China (No.20100061120087)the Postdoctoral Science Foundation of China(No.20090451146)
文摘1 IntroductionIn the very recent years, low-dimensional nanomaterials have attracted a great interest in nanoscience and nanotechnology due to their exciting application in electronics[1], optoelectronics[2] and mechanics[3] in nanoscale. Compared to bulk materials,
文摘ZnS films were successfully grown by metallorganic chemical vapour deposition (MOCVD) at atmospheric pressure on (100) GaAs substrates. The deposition was carried out at a substrate temperature between 280 approximately 550°C with optimisation of reactor design and growth conditions. The gas phase prereaction is effectively restrained. These epilayers exhibit high crystallographic quality and reveal a mirror surface morphology. The peak halfwidths of X-ray diffraction patterns from their (400) faces are within 0.06 approximately 0.09°. The epilayers grown on (111) GaAs, (112¯0) Al2O3 and (100) Si have proven to be single crystalline feature. The optical and electrical characteristics of ZnS epilayers are measured by photoluminescence, cathodeluminescence, and the Van der Pauw method. The results indicate that there are not a large number of deep centers that could be detected both at 77K and at room temperature. A broad CL peak around 2.897eV and 2.672eV was observed only under very strong excitation. Their origin has not been examined. All epilayers present high resistivities up to 1013Ω·cm.
