Lattice matched Ga1-x Inx Asy Sb1-y quaternary alloy films for thermophotovoltaic cells were successfully grown on n-type GaSb substrates by liquid phase epitaxy. Mirror-like surfaces for the epitaxial layers were ach...Lattice matched Ga1-x Inx Asy Sb1-y quaternary alloy films for thermophotovoltaic cells were successfully grown on n-type GaSb substrates by liquid phase epitaxy. Mirror-like surfaces for the epitaxial layers were achieved and evaluated by atomic force microscopy. The composition of the Ga1-x Inx Asy Sb1-y layer was characterized by energy dispersive X-ray analysis with the result that x- 0.2, y = 0.17. The absorption edges of the Ga1-x InxAsy Sb1-y films were determined to be 2. 256μm at room temperature by Fourier transform infrared transmission spectrum analysis, corresponding to an energy gap of 0.55eV. Hall measurements show that the highest obtained electron mobility in the undoped p-type samples is 512cm^2/（V · s） and the carrier density is 6.1 × 10^16 cm^-3 at room temperature. Finally,GaInAsSb based thermophotovol- taic cells in different structures with quantum efficiency values of around 60% were fabricated and the spectrum response characteristics of the cells are discussed.展开更多
MOCVD growth and characterization of GaSb rich and InAs rich GaInAsSb on GaSb substrates were investigated. The surface of InAs rich GaInAsSb epilayer was different from GaSb rich film. The flux of TMSb in vapor p...MOCVD growth and characterization of GaSb rich and InAs rich GaInAsSb on GaSb substrates were investigated. The surface of InAs rich GaInAsSb epilayer was different from GaSb rich film. The flux of TMSb in vapor phase might be the cause of the different surface features between GaSb rich and InAs rich epilayers. The n type conduction of InAs rich GaInAsSb was also different from GaSb rich samples. The p type conduction is often attributed to native lattice defect or carbon impurity on group Ⅴ sites. Carbon might occupies group Ⅲ sites as donor in InAs rich GaInAsSb film. The strength of the chemical bonding between carbon and group Ⅲ or group Ⅴ elements had much to do with the carbon impurity site preference, resulting in the two type conductions of GaInAsSb film grown by MOCVD.展开更多
he pattern recognition method and artificial neural network method to predict the composition of epilayer of GaInAsSb by MOCVD. It is concluded that a neural network with the composition of the vapor phase and growth ...he pattern recognition method and artificial neural network method to predict the composition of epilayer of GaInAsSb by MOCVD. It is concluded that a neural network with the composition of the vapor phase and growth temperature as training data can predict the composition of the epilayers. Satisfactory pattern recognition and artificial neural network classification results were obtained by using four technical parameters as characteristic features and the epilayers composition as classification criteria.展开更多
Growth of GaInAsSb epilayer by liquid phase epitaxy (LPE) was reported. The LPE system with a hor-izontal sliding graphite boat was employed. The Te-doped (100) GaSb wafer was chosen as substrate. Thephysical properti...Growth of GaInAsSb epilayer by liquid phase epitaxy (LPE) was reported. The LPE system with a hor-izontal sliding graphite boat was employed. The Te-doped (100) GaSb wafer was chosen as substrate. Thephysical properties of the GalnAsSb / GaSb heterostructure were investigated by double crystal X-ray rock-ing diffraction and photoluminescence. The p-GaInAsSb/ n-GaSb photodiode was made by using theseheterostructure materials .The detectivity of the photodiode D* is 4.65 ×10￣9 cm . Hz￣(1 /2) W￣(-1).展开更多
Scanning electron acoustic microscopy (SEAM) is a new technique for imasing and characterization ofthermal, elastic and pyroelectric property variations on a microscale resolution. The signal generation mechanisms and...Scanning electron acoustic microscopy (SEAM) is a new technique for imasing and characterization ofthermal, elastic and pyroelectric property variations on a microscale resolution. The signal generation mechanisms and the application of scanning electron acoustic microscopy in GalnAsSb alloy grown by MOCVD wereinvestigated. Defects below the surface of GalnAsSb alloy were found by SEAM images and cathodelumi-nescence. The results show that electronacoustic imaging has its own features over secondary electron imag-ing.展开更多
从非平衡载流子的扩散 -复合理论出发 ,提出 PIN多结探测器材料结构 ,并建立了理论模型进行定量计算 ,从理论上解决了不能同时兼顾增大量子效率与光电增益和降低噪声的矛盾。利用该模型对 Ga In As Sb材料体系作了数值模拟 ,单结器件性...从非平衡载流子的扩散 -复合理论出发 ,提出 PIN多结探测器材料结构 ,并建立了理论模型进行定量计算 ,从理论上解决了不能同时兼顾增大量子效率与光电增益和降低噪声的矛盾。利用该模型对 Ga In As Sb材料体系作了数值模拟 ,单结器件性能的计算值和实测值基本吻合 ,并根据多结器件模拟结果设计了工作于2 .4μm波段的 Ga In As Sb展开更多
By analyzing the main recombination mechanisms in GaInAsSb materials, the dependences of the dark current density and open circuit voltage in n+-p GaInAsSb thermophotovoltaic cells on the recombination parameters, car...By analyzing the main recombination mechanisms in GaInAsSb materials, the dependences of the dark current density and open circuit voltage in n+-p GaInAsSb thermophotovoltaic cells on the recombination parameters, carrier concentration and cell thickness are calculated. The results show that the dark current mainly comes from p-region, and it is related with the surface and Auger recombinations in low and high carrier concentration ranges, respectively. The surface and Auger recombinations can be suppressed by reducing the surface recombination velocity and carrier concentration, respectively. The dark current density can be suppressed by optimizing material parameters and device surface passivation technique. So the high open circuit voltage can be obtained for GaInAsSb thermophotovoltaic cells.展开更多
The properties of GaSb substrates commonly used for the preparation of Ⅲ Ⅴ antimonide epilayers were studied before and after growing GaInAsSb multi layers by MOCVD using PL, FTIR and DCXD together with the electr...The properties of GaSb substrates commonly used for the preparation of Ⅲ Ⅴ antimonide epilayers were studied before and after growing GaInAsSb multi layers by MOCVD using PL, FTIR and DCXD together with the electrical properties and EPD values. The correlation between the substrate qualities and epilayer properties was briefly discussed. The good property epilayers of GaInAsSb and, then, the high performance of 2.3 μm photodetectors were achieved only when the good quality GaSb wafers was used as the substrates.展开更多
文摘Lattice matched Ga1-x Inx Asy Sb1-y quaternary alloy films for thermophotovoltaic cells were successfully grown on n-type GaSb substrates by liquid phase epitaxy. Mirror-like surfaces for the epitaxial layers were achieved and evaluated by atomic force microscopy. The composition of the Ga1-x Inx Asy Sb1-y layer was characterized by energy dispersive X-ray analysis with the result that x- 0.2, y = 0.17. The absorption edges of the Ga1-x InxAsy Sb1-y films were determined to be 2. 256μm at room temperature by Fourier transform infrared transmission spectrum analysis, corresponding to an energy gap of 0.55eV. Hall measurements show that the highest obtained electron mobility in the undoped p-type samples is 512cm^2/（V · s） and the carrier density is 6.1 × 10^16 cm^-3 at room temperature. Finally,GaInAsSb based thermophotovol- taic cells in different structures with quantum efficiency values of around 60% were fabricated and the spectrum response characteristics of the cells are discussed.
文摘MOCVD growth and characterization of GaSb rich and InAs rich GaInAsSb on GaSb substrates were investigated. The surface of InAs rich GaInAsSb epilayer was different from GaSb rich film. The flux of TMSb in vapor phase might be the cause of the different surface features between GaSb rich and InAs rich epilayers. The n type conduction of InAs rich GaInAsSb was also different from GaSb rich samples. The p type conduction is often attributed to native lattice defect or carbon impurity on group Ⅴ sites. Carbon might occupies group Ⅲ sites as donor in InAs rich GaInAsSb film. The strength of the chemical bonding between carbon and group Ⅲ or group Ⅴ elements had much to do with the carbon impurity site preference, resulting in the two type conductions of GaInAsSb film grown by MOCVD.
文摘he pattern recognition method and artificial neural network method to predict the composition of epilayer of GaInAsSb by MOCVD. It is concluded that a neural network with the composition of the vapor phase and growth temperature as training data can predict the composition of the epilayers. Satisfactory pattern recognition and artificial neural network classification results were obtained by using four technical parameters as characteristic features and the epilayers composition as classification criteria.
文摘Growth of GaInAsSb epilayer by liquid phase epitaxy (LPE) was reported. The LPE system with a hor-izontal sliding graphite boat was employed. The Te-doped (100) GaSb wafer was chosen as substrate. Thephysical properties of the GalnAsSb / GaSb heterostructure were investigated by double crystal X-ray rock-ing diffraction and photoluminescence. The p-GaInAsSb/ n-GaSb photodiode was made by using theseheterostructure materials .The detectivity of the photodiode D* is 4.65 ×10￣9 cm . Hz￣(1 /2) W￣(-1).
文摘Scanning electron acoustic microscopy (SEAM) is a new technique for imasing and characterization ofthermal, elastic and pyroelectric property variations on a microscale resolution. The signal generation mechanisms and the application of scanning electron acoustic microscopy in GalnAsSb alloy grown by MOCVD wereinvestigated. Defects below the surface of GalnAsSb alloy were found by SEAM images and cathodelumi-nescence. The results show that electronacoustic imaging has its own features over secondary electron imag-ing.
文摘从非平衡载流子的扩散 -复合理论出发 ,提出 PIN多结探测器材料结构 ,并建立了理论模型进行定量计算 ,从理论上解决了不能同时兼顾增大量子效率与光电增益和降低噪声的矛盾。利用该模型对 Ga In As Sb材料体系作了数值模拟 ,单结器件性能的计算值和实测值基本吻合 ,并根据多结器件模拟结果设计了工作于2 .4μm波段的 Ga In As Sb
基金supported by the National Natural Science Foundation of China(No.60676040)the Fund of State Key Laboratory on Integrated Optoelectronics
文摘By analyzing the main recombination mechanisms in GaInAsSb materials, the dependences of the dark current density and open circuit voltage in n+-p GaInAsSb thermophotovoltaic cells on the recombination parameters, carrier concentration and cell thickness are calculated. The results show that the dark current mainly comes from p-region, and it is related with the surface and Auger recombinations in low and high carrier concentration ranges, respectively. The surface and Auger recombinations can be suppressed by reducing the surface recombination velocity and carrier concentration, respectively. The dark current density can be suppressed by optimizing material parameters and device surface passivation technique. So the high open circuit voltage can be obtained for GaInAsSb thermophotovoltaic cells.
文摘The properties of GaSb substrates commonly used for the preparation of Ⅲ Ⅴ antimonide epilayers were studied before and after growing GaInAsSb multi layers by MOCVD using PL, FTIR and DCXD together with the electrical properties and EPD values. The correlation between the substrate qualities and epilayer properties was briefly discussed. The good property epilayers of GaInAsSb and, then, the high performance of 2.3 μm photodetectors were achieved only when the good quality GaSb wafers was used as the substrates.
