利用 X 射线衍射(XRD),X 射线摇摆曲线(XRC)和 X 射线光电子能谱(XPS)分析方法对氧离子束辅助激光淀积生长的 ZnO/Si 异质结薄膜进行了分析。结果表明:用该法可生长出高度 c 轴单一取向 ZnO 薄膜,XRC 的半高宽度(FWHM)仅为2.918°...利用 X 射线衍射(XRD),X 射线摇摆曲线(XRC)和 X 射线光电子能谱(XPS)分析方法对氧离子束辅助激光淀积生长的 ZnO/Si 异质结薄膜进行了分析。结果表明:用该法可生长出高度 c 轴单一取向 ZnO 薄膜,XRC 的半高宽度(FWHM)仅为2.918°。表明此生长方法经优化,可生长出单晶质量很好的 ZnO/Si 薄膜。展开更多
The preparation of high quality ZnO/Si substrates for the growth of GaN blue light emitting materials is considered. ZnO thin films have been deposited on Si (100) and Si (111) substrates by conventional magnetron spu...The preparation of high quality ZnO/Si substrates for the growth of GaN blue light emitting materials is considered. ZnO thin films have been deposited on Si (100) and Si (111) substrates by conventional magnetron sputtering. Morphology, crystallinity and c-axis preferred orientation of ZnO thin films have been investigated by transmitting electron microscopy (TEM), X-ray diffraction (XRD) and X-ray rocking curve (XRC). It is proved that the ZnO thin films have perfect structure. The full-width-at-half-maximum (FWHM) of the ZnO(002) XRC of these films is about 1°, while the minimum is 0.353°. This result is better than the minimum FWHM (about 2°) reported by other research groups. Moreover, comparison and discussion are given on film structure of ZnO/Si(100) and ZnO/Si(111).展开更多
采用改进的布里奇曼法生长出尺寸为Φ15 mm×45 mm,外观完整无开裂的Cd Ge As2单晶体。为了提高器件的使用性能,需要对晶体进行表面处理,主要对Cd Ge As2晶片表面的抛光技术进行了研究。通过对解理面切割分析得到(101)晶面,机械抛...采用改进的布里奇曼法生长出尺寸为Φ15 mm×45 mm,外观完整无开裂的Cd Ge As2单晶体。为了提高器件的使用性能,需要对晶体进行表面处理,主要对Cd Ge As2晶片表面的抛光技术进行了研究。通过对解理面切割分析得到(101)晶面,机械抛光后进行了XPS分析。对该晶面采用溴甲醇溶液进行腐蚀抛光,采用XRD回摆及光学显微镜对不同抛光时间的试样进行观测。结果表明,CGA晶体的(101)晶面在常温下采用溴甲醇溶液腐蚀50 s后,晶片表面光滑无划痕,并且具有半峰宽较小的回摆曲线,同时计算得到Cd Ge As2晶体的表面损伤层厚度。展开更多
AlGaAs/GaAs multi-quantum well (MQW) was prepared by molecular beam epitaxy(MBE) with growth-interrupted heterointerface (GIH) method and continuous growth (CG) method, respectively. The microstructures of the MQWs we...AlGaAs/GaAs multi-quantum well (MQW) was prepared by molecular beam epitaxy(MBE) with growth-interrupted heterointerface (GIH) method and continuous growth (CG) method, respectively. The microstructures of the MQWs were characterized by double-crystal X-ray rocking curve (DCRC) and atomic force microscopy (AFM), and the photoluminescence (PL) properties of the MQWs were also studied. The MQWs grown with GIH method show that higher order satellite peaks of Pendell?sung fringes are observed in DCRC, the roughness of surface is much reduced in AFM, and the full width at half maximum (FWHM) of exciton line is much narrower in PL. The results indicate that the GIH method reduces the monolayer growth step density at the heterointerface due to the migration of surface atoms for a few minutes growth interruption, and substantially improves the quality of AlGaAs/GaAs MQWs.展开更多
We have grown underdoped （х = 0.11, 0.12） and optimally doped （x = 0.16）La2-хSrхCuO4 single crystals by the traveling-solvent floating-zone technique.In order to prepare good quality cuprate crystals,we have ma...We have grown underdoped （х = 0.11, 0.12） and optimally doped （x = 0.16）La2-хSrхCuO4 single crystals by the traveling-solvent floating-zone technique.In order to prepare good quality cuprate crystals,we have made much effort to optimize the preparation procedures.For example,we haveadopted the sol-gel route to prepare a highly fine and homogeneous La2-хSrхCuO4 precursor powder for fabricating a very dense ceramic feed rod used for the floating-zone growth,and we have also used quite a slow growth rate. The high quality of the grown crystals has been verified by double-crystal x-ray rocking curves,with the full-width-at-half-maximum being only 113-150 arcseconds, which are the best data reported so far for La2-хSrхCuO4 crystals.The superconducting critical temperatures of the grown crystals are 30, 31 and 38.5 K for х = 0.11, 0.12 and 0.16 samples, respectively,according to magnetic measurements.展开更多
文摘利用 X 射线衍射(XRD),X 射线摇摆曲线(XRC)和 X 射线光电子能谱(XPS)分析方法对氧离子束辅助激光淀积生长的 ZnO/Si 异质结薄膜进行了分析。结果表明:用该法可生长出高度 c 轴单一取向 ZnO 薄膜,XRC 的半高宽度(FWHM)仅为2.918°。表明此生长方法经优化,可生长出单晶质量很好的 ZnO/Si 薄膜。
文摘The preparation of high quality ZnO/Si substrates for the growth of GaN blue light emitting materials is considered. ZnO thin films have been deposited on Si (100) and Si (111) substrates by conventional magnetron sputtering. Morphology, crystallinity and c-axis preferred orientation of ZnO thin films have been investigated by transmitting electron microscopy (TEM), X-ray diffraction (XRD) and X-ray rocking curve (XRC). It is proved that the ZnO thin films have perfect structure. The full-width-at-half-maximum (FWHM) of the ZnO(002) XRC of these films is about 1°, while the minimum is 0.353°. This result is better than the minimum FWHM (about 2°) reported by other research groups. Moreover, comparison and discussion are given on film structure of ZnO/Si(100) and ZnO/Si(111).
基金National Natural Science Foundation of China(50732005)National High Technology Research and Development Program of China(2007AA03Z443)
文摘采用改进的布里奇曼法生长出尺寸为Φ15 mm×45 mm,外观完整无开裂的Cd Ge As2单晶体。为了提高器件的使用性能,需要对晶体进行表面处理,主要对Cd Ge As2晶片表面的抛光技术进行了研究。通过对解理面切割分析得到(101)晶面,机械抛光后进行了XPS分析。对该晶面采用溴甲醇溶液进行腐蚀抛光,采用XRD回摆及光学显微镜对不同抛光时间的试样进行观测。结果表明,CGA晶体的(101)晶面在常温下采用溴甲醇溶液腐蚀50 s后,晶片表面光滑无划痕,并且具有半峰宽较小的回摆曲线,同时计算得到Cd Ge As2晶体的表面损伤层厚度。
文摘AlGaAs/GaAs multi-quantum well (MQW) was prepared by molecular beam epitaxy(MBE) with growth-interrupted heterointerface (GIH) method and continuous growth (CG) method, respectively. The microstructures of the MQWs were characterized by double-crystal X-ray rocking curve (DCRC) and atomic force microscopy (AFM), and the photoluminescence (PL) properties of the MQWs were also studied. The MQWs grown with GIH method show that higher order satellite peaks of Pendell?sung fringes are observed in DCRC, the roughness of surface is much reduced in AFM, and the full width at half maximum (FWHM) of exciton line is much narrower in PL. The results indicate that the GIH method reduces the monolayer growth step density at the heterointerface due to the migration of surface atoms for a few minutes growth interruption, and substantially improves the quality of AlGaAs/GaAs MQWs.
基金Project supported by the State Key Development Program for Basic Research of China (Grant No 2006CB0L0302)the National Natural Science Foundation of China (Grant No 10574149)
文摘We have grown underdoped （х = 0.11, 0.12） and optimally doped （x = 0.16）La2-хSrхCuO4 single crystals by the traveling-solvent floating-zone technique.In order to prepare good quality cuprate crystals,we have made much effort to optimize the preparation procedures.For example,we haveadopted the sol-gel route to prepare a highly fine and homogeneous La2-хSrхCuO4 precursor powder for fabricating a very dense ceramic feed rod used for the floating-zone growth,and we have also used quite a slow growth rate. The high quality of the grown crystals has been verified by double-crystal x-ray rocking curves,with the full-width-at-half-maximum being only 113-150 arcseconds, which are the best data reported so far for La2-хSrхCuO4 crystals.The superconducting critical temperatures of the grown crystals are 30, 31 and 38.5 K for х = 0.11, 0.12 and 0.16 samples, respectively,according to magnetic measurements.
