Precipitates in undoped GaN epilayers with specular surfaces grown on sapphire substrates were imaged by super high-resolution electron microscopy(HREM)and analyzed by energy-dispersive x-ray spectrometry(EDXS).The HR...Precipitates in undoped GaN epilayers with specular surfaces grown on sapphire substrates were imaged by super high-resolution electron microscopy(HREM)and analyzed by energy-dispersive x-ray spectrometry(EDXS).The HREM images of the precipitates appeared more or less hexagonal intersection with several ten-nanometer large,which is the same as that of the V-shape defects.The EDXS spectra of the precipitates were mainly composed of the characteristic x-rays of oxygen,carbon,and gallium elements.The results suggest that the precipitates nucleate at the pinholes of the V-shape cavities and grow as the GaN growth.展开更多
Fine structure in the electron emission process for DX(Sn)centers in AlGaAs has been studied with high resolution Laplace defect spectroscopy.The influence of the different local configuration of Al and Ga atoms aroun...Fine structure in the electron emission process for DX(Sn)centers in AlGaAs has been studied with high resolution Laplace defect spectroscopy.The influence of the different local configuration of Al and Ga atoms around the centers on the electron thermal emissions was observed.An experimental evidence for the microscopic structure of two DX-like centers in Sn-doped AlGaAs is provided.展开更多
基金Supported in part by the National Natural Science Foundation of China under Grant No.69576022Natural Science Foundation of Fujian Provincethe Research Funds of Japan Society for the Future Program on "Atomic Scale Surface and Interface Dynamics".
文摘Precipitates in undoped GaN epilayers with specular surfaces grown on sapphire substrates were imaged by super high-resolution electron microscopy(HREM)and analyzed by energy-dispersive x-ray spectrometry(EDXS).The HREM images of the precipitates appeared more or less hexagonal intersection with several ten-nanometer large,which is the same as that of the V-shape defects.The EDXS spectra of the precipitates were mainly composed of the characteristic x-rays of oxygen,carbon,and gallium elements.The results suggest that the precipitates nucleate at the pinholes of the V-shape cavities and grow as the GaN growth.
基金Supported by the National Natural Science Foundation of China under Grant No.69576022Natural Science Foundation of Fujian Province of China。
文摘Fine structure in the electron emission process for DX(Sn)centers in AlGaAs has been studied with high resolution Laplace defect spectroscopy.The influence of the different local configuration of Al and Ga atoms around the centers on the electron thermal emissions was observed.An experimental evidence for the microscopic structure of two DX-like centers in Sn-doped AlGaAs is provided.
