Thermal annealing in Te vapor atmosphere was adopted to improve the properties of indium-doped Cd_(1-x)Mn_xTe(x=0.2,CdMnTe) wafers grown by the vertical Bridgman method.The wafers before and after annealing were chara...Thermal annealing in Te vapor atmosphere was adopted to improve the properties of indium-doped Cd_(1-x)Mn_xTe(x=0.2,CdMnTe) wafers grown by the vertical Bridgman method.The wafers before and after annealing were characterized by measuring the Te inclusions,etch pit density(EPD),Mn composition,resistivity, and impurity.IR transmission microscopy and EPD measurements revealed that the densities of Te inclusions reduced from(5-9)×10~4 cm^(-3) to(2-4)×10~4 cm^(-3) and EPD from 10~5 cm^(-2) to 10~4 cm^(-2) after annealing. NIR transmission spectroscopy showed that the Mn composition increased by 0.002-0.005 mole fractions during the annealing.The resistivity of the wafers improved from(2.0-4.5)×10~8Ω·cm to(1.7-3.8)×10~9Ω·cm,which suggested that the deep-level donor of Te antisites was successfully introduced after annealing.Inductively coupled plasma-mass spectrometry(ICP-MS) revealed that the concentrations of impurities in the wafer decreased,which indicated the purifying effects of Te vapor annealing on the wafers.All the results demonstrate that the Te vapor annealing of the indium-doped CdMnTe crystal has positive effects on the crystallinity,resistivity and purity of CdMnTe wafers.展开更多
The spatial and temporal distributions of the stable isotopes such as HD16O （or 1H2H16O, or HDO） and H2 18O in atmospheric water vapor are related to evaporation in source places, vapor condensation during transport...The spatial and temporal distributions of the stable isotopes such as HD16O （or 1H2H16O, or HDO） and H2 18O in atmospheric water vapor are related to evaporation in source places, vapor condensation during transport, and vapor convergence and divergence, and thus provide useful information for investigation and understanding of the global water cycle. This paper analyzes spatiotemporal variations of the content of iso- tope HDO （i.e., 5D）, in atmospheric water vapor, namely, δDv, and the relationship of δDv with atmospheric humidity and temperature at different levels in the troposphere, using the HDO and H2O data retrieved from the Tropospheric Emission Spectrometer （TES） at seven pressure levels from 825 to 100 hPa. The results indicate that δDv has a clear zonal distribution in the troposphere and a good correspondence with atmospheric precipitable water. The results also show that δDv decreases logarithmically with atmospheric pressure and presents a decreasing trend from the equator to high latitudes and from lands to oceans. Sea- sonal changes of δDv exhibit regional differences. The spatial distribution and seasonal variation of δDv in the low troposphere are consistent with those in the middle troposphere, but opposite situations occur from the upper troposphere to the lower stratosphere. The correlation between δDv and temperature has a similar distribution pattern to the correlation between δDv and precipitable water in the troposphere. The stable isotope HDO in water vapor （δDv）, compared with that in precipitation （δDp）, is of some differences in spatial distribution and seasonal variation, and in its relationship with temperature and humidity, in- dicating that the impacts of stable isotopic fractionation and atmospheric circulation on the two types of stable isotopes are different.展开更多
基金supported by the National Natural Science Foundations of China(No.50902091)the Science and Technology Commission of Shanghai,China(No.11530500200)+1 种基金the Innovation Program of Shanghai Municipal Education Commission,China(No.12ZZ096)the Innovative Foundation of Shanghai University,China
文摘Thermal annealing in Te vapor atmosphere was adopted to improve the properties of indium-doped Cd_(1-x)Mn_xTe(x=0.2,CdMnTe) wafers grown by the vertical Bridgman method.The wafers before and after annealing were characterized by measuring the Te inclusions,etch pit density(EPD),Mn composition,resistivity, and impurity.IR transmission microscopy and EPD measurements revealed that the densities of Te inclusions reduced from(5-9)×10~4 cm^(-3) to(2-4)×10~4 cm^(-3) and EPD from 10~5 cm^(-2) to 10~4 cm^(-2) after annealing. NIR transmission spectroscopy showed that the Mn composition increased by 0.002-0.005 mole fractions during the annealing.The resistivity of the wafers improved from(2.0-4.5)×10~8Ω·cm to(1.7-3.8)×10~9Ω·cm,which suggested that the deep-level donor of Te antisites was successfully introduced after annealing.Inductively coupled plasma-mass spectrometry(ICP-MS) revealed that the concentrations of impurities in the wafer decreased,which indicated the purifying effects of Te vapor annealing on the wafers.All the results demonstrate that the Te vapor annealing of the indium-doped CdMnTe crystal has positive effects on the crystallinity,resistivity and purity of CdMnTe wafers.
基金Supported by the National Natural Science Foundation of China (40871094 and 41171035)Construction Program of the Key Discipline in Hunan Province (2012001)+1 种基金Open Fund of Key Laboratory of Tibetan Environment Changes and Land Surface Processes of the Chinese Academy of Sciences (2011004)Scientific Research Fund of Hunan Provincial Education Department (09A056)
文摘The spatial and temporal distributions of the stable isotopes such as HD16O （or 1H2H16O, or HDO） and H2 18O in atmospheric water vapor are related to evaporation in source places, vapor condensation during transport, and vapor convergence and divergence, and thus provide useful information for investigation and understanding of the global water cycle. This paper analyzes spatiotemporal variations of the content of iso- tope HDO （i.e., 5D）, in atmospheric water vapor, namely, δDv, and the relationship of δDv with atmospheric humidity and temperature at different levels in the troposphere, using the HDO and H2O data retrieved from the Tropospheric Emission Spectrometer （TES） at seven pressure levels from 825 to 100 hPa. The results indicate that δDv has a clear zonal distribution in the troposphere and a good correspondence with atmospheric precipitable water. The results also show that δDv decreases logarithmically with atmospheric pressure and presents a decreasing trend from the equator to high latitudes and from lands to oceans. Sea- sonal changes of δDv exhibit regional differences. The spatial distribution and seasonal variation of δDv in the low troposphere are consistent with those in the middle troposphere, but opposite situations occur from the upper troposphere to the lower stratosphere. The correlation between δDv and temperature has a similar distribution pattern to the correlation between δDv and precipitable water in the troposphere. The stable isotope HDO in water vapor （δDv）, compared with that in precipitation （δDp）, is of some differences in spatial distribution and seasonal variation, and in its relationship with temperature and humidity, in- dicating that the impacts of stable isotopic fractionation and atmospheric circulation on the two types of stable isotopes are different.
