利用TFC光学膜系设计软件,设计出空间用GaInP/(In)GaAs/Ge三结太阳电池的分布式布拉格反射器(DBR)。由15对Al0.2Ga0.8As/Al0.9Ga0.1As组成的布拉格反射器在中心波长850 nm处反射率高达96%,可以使800~900 nm波段内红外光有效反射后被二...利用TFC光学膜系设计软件,设计出空间用GaInP/(In)GaAs/Ge三结太阳电池的分布式布拉格反射器(DBR)。由15对Al0.2Ga0.8As/Al0.9Ga0.1As组成的布拉格反射器在中心波长850 nm处反射率高达96%,可以使800~900 nm波段内红外光有效反射后被二次吸收,提高了Ga As子电池的抗辐照能力。通过对两种电池结构A、B地面模拟辐照试验获得1 Me V电子辐照下Ga In P/Ga As/Ge太阳电池电学参数随辐照注量退化的基本规律。在此基础上应用PC1D模拟程序分析太阳电池内部的载流子输运机理,建立1 Me V电子辐照下两种电池结构中多数载流子浓度和少数载流子扩散长度随辐照电子注量变化的基本规律。研究结果表明,多数载流子浓度和少数载流子扩散长度均随入射电子注量的增大而减小,同时原电池结构A中多数载流子去除率和少数载流子扩散长度损伤系数明显高于新电池结构B,由此表明包含布拉格反射器的新电池结构具有更强的抗辐照能力。展开更多
Orbital experimental researches on crystal growth of Mn-doped GaSb and Bi2Se0.21Te2.79 are briefly summarized.The space experiments were completed in September of 2007 on broad the Foton-M3 satellite of Russia.Ground-...Orbital experimental researches on crystal growth of Mn-doped GaSb and Bi2Se0.21Te2.79 are briefly summarized.The space experiments were completed in September of 2007 on broad the Foton-M3 satellite of Russia.Ground-based researches on the solidification behaviors of Al-Al3Ni,AlAl2Cu,Ag-Cu eutectic,Al-Pb monotectic and Cu-Co peritectic alloys in a 50-meter-high drop tube were investigated.New experimental results on the ultrasonic field and the temperature recycling induced to chiral symmetry breaking of NaClO3 crystal also were reported in the present paper.展开更多
The Engineering of Chinese Spacecraft provides Chinese scientists of materials great opportunity in the experiments for preparing materials under microgravity. On board of Spacecraft-Shenzhou No.3 (SZ-3), alloys a... The Engineering of Chinese Spacecraft provides Chinese scientists of materials great opportunity in the experiments for preparing materials under microgravity. On board of Spacecraft-Shenzhou No.3 (SZ-3), alloys and semiconductors, such as Al Mg2Si, Nd60Al10Fe20Co10, Pd40Ni10Cu30P20, Al-Al3Ni, GaMnSb, Bi12SiO20:Ce, and Cd0.96Zn0.04Te:Ge, were prepared. SZ-3 successfully returned to the earth on April 1, 2002. Profiting from SZ-3, great progress has been made in the researches on ma terials under microgravity in space. The quartz ampoules containing the materials grown on board of SZ-3 were shown in CFig. 1 (see the Appendix). The properties of the materials prepared on board of SZ-3 are still under investigation.……展开更多
CeO2 thin film was fabricated by dual ion beam epitaxial technique. The phenomenon of PL violet shift at room temperature was observed, and the distance of shift was about 65 nm. After the analysis of crystal structur...CeO2 thin film was fabricated by dual ion beam epitaxial technique. The phenomenon of PL violet shift at room temperature was observed, and the distance of shift was about 65 nm. After the analysis of crystal structure and valence in the compound were carried out by XRD and XPS technique, it was concluded that the PL shift was related with valence of cerium ion in the oxides. When the valence of cerium ion varied from tetravalence to trivalence, the PL peak position would move from blue region to violet region and the phenomenon of 'violet shift' was observed.展开更多
A model for analyzing point defects in com-pound crystals was improved. Based on this modified model, a method for measuring Mn content in GaMnAs was estab-lished. A technique for eliminating the zero-drift-error was ...A model for analyzing point defects in com-pound crystals was improved. Based on this modified model, a method for measuring Mn content in GaMnAs was estab-lished. A technique for eliminating the zero-drift-error was also established in the experiments of X-ray diffraction. With these methods, the Mn content in GaMnAs single crystals fabricated by the ion-beam epitaxy system was analyzed.展开更多
GaInP/GaAs dual-junction solar cell with a conversion efficiency of 25.2% has been fabricated using metalorganic chemical vapor deposition (MOCVD) technique. Quantum efficiencies of the solar cell were measured within...GaInP/GaAs dual-junction solar cell with a conversion efficiency of 25.2% has been fabricated using metalorganic chemical vapor deposition (MOCVD) technique. Quantum efficiencies of the solar cell were measured within a temperature range from 25 to 160°C. The results indicate that the quantum efficiencies of the subcells increase slightly with the increasing temperature. And red-shift phenomena of absorption limit for all subcells are observed by increasing the cell’s work temperature, which are consistent with the viewpoint of energy gap narrowing effect. The short-circuit current density temperature coefficients dJ sc/dT of GaInP subcell and GaAs subcell are determined to be 8.9 and 7.4 μA/cm2/°C from the quantum efficiency data, respectively. And the open-circuit cell voltage temperature coefficients dV oc/dT calculated based on a theoretical equation are ?2.4 mV/°C and ?2.1 mV/°C for GaInP subcell and GaAs subcell.展开更多
Ag nanoparticles were fabricated on Si substrates by radio-frequency magnetron sputtering and thermal annealing treatments.It was found that Ag nanoparticles are ellipsoid at low annealing temperature,but the axis rat...Ag nanoparticles were fabricated on Si substrates by radio-frequency magnetron sputtering and thermal annealing treatments.It was found that Ag nanoparticles are ellipsoid at low annealing temperature,but the axis ratio decreases with the increase of annealing temperature,and a shape transformation from ellipsoid to sphere occurs when the temperature increases to a critical point.The experimental results showed that the surface plasmon resonances depend greatly on the nanoparticles'shape and size,which is in accordance with the theoretical calculation based on discrete dipole approximation.The results of forward-scattering efficiency(FSE) and light trapping spectrum(LTS) showed that Ag nanoparticles annealed at 400°C could strongly enhance the light harvest than those annealed at 300 and 500°C,and that the LTS peak intensity of the former is 1.7 and 1.5 times stronger than those of the later two samples,respectively.The conclusions obtained in this paper showed that Ag ellipsoid nanoparticles with appropriate size is more favorable for enhancing the light trapping.展开更多
Depth profiles of carrier concentrations in Ga-MnSb/GaSb are investigated by electrochemistry capacitance-voltage profiler and electrolyte of Tiron. The carrier concentration in GaMnSb/GaSb measured by this method is ...Depth profiles of carrier concentrations in Ga-MnSb/GaSb are investigated by electrochemistry capacitance-voltage profiler and electrolyte of Tiron. The carrier concentration in GaMnSb/GaSb measured by this method is coincident with the results of Hall and X-ray diffraction measurements. It is indicated that most of the Mn atoms in GaMnSb take the site of Ga, play a role of acceptors, and provide shallow acceptor level(s).展开更多
A polycrystalline silicon thin film was fabricated on glass substrate by means of aluminum induced crystallization (AIC). Al and α-Si layers were deposited by magnetron sputtering respectively and annealed at 480...A polycrystalline silicon thin film was fabricated on glass substrate by means of aluminum induced crystallization (AIC). Al and α-Si layers were deposited by magnetron sputtering respectively and annealed at 480°C for 1 h to realize layer exchange. The polycrystalline silicon thin film was continuous and strongly (111) oriented. By analyzing the structure variation of the oxidation membrane and lattice mismatch between γ-Al2O3 and Si, it was concluded that aluminum promoted the formation of (111) oriented silicon nucleus by controlling the orientation of γ-Al2O3, which was formed at the early stage of annealing.展开更多
Previous reports about the thermal conductivities of VO2 showed various temperature dependences across metal-insulator transition (MIT) temperature. In this work, polycrystalline VO2 samples were fabricated by spark p...Previous reports about the thermal conductivities of VO2 showed various temperature dependences across metal-insulator transition (MIT) temperature. In this work, polycrystalline VO2 samples were fabricated by spark plasma sintering of VO2 powder. Temperature dependences of their thermal conductivities were investigated using laser flash technique, and the thermal conductivity showed a significant decrease trend from metal-phase to insulator phase. Electrical transport properties were investigated to confirm both carrier and lattice contribution to the thermal conductivity. It is found that the lattice thermal conductivity decreased significantly across MIT point, which may be caused by soft phonon mode in metal phase of VO2 .展开更多
A novel interconnected structure consisting of a conventional polyimide layer(PM) and an additional SiO2/TiAu/SiO2 sandwich multilayer has been firstly proposed for improving the performance of GaAs micro-solar cell a...A novel interconnected structure consisting of a conventional polyimide layer(PM) and an additional SiO2/TiAu/SiO2 sandwich multilayer has been firstly proposed for improving the performance of GaAs micro-solar cell array.The specific experimental investigations on the array with 108 unit cells have demonstrated that the novel structure of PM/SiO2/TiAu/SiO2 can effectively enhance the open-circuit voltage from 75 to 84 V and the fill factor from 35% to 57%.The performance improvement of our devices can be attributed to two aspects.Firstly,the TiAu shielding film can prevent the incident light from penetrating into the GaAs substrate so as to induce the serious substrate leakage current.Secondly,the compact texture of SiO2 in the novel structure can reduce the perimere recombination due to the crackle or shrinkage of PM.It is indicated that the novel structure can distinctly reduce the leakage current and improve output characteristic of micro-solar cells.展开更多
GalnP/GaAs/Ge tandem solar cells were fabricated by a MOCVD technique.The photoelectric properties of the solar cells were characterized by a current-voltage test method.The dependence of the solar cell’s characteris...GalnP/GaAs/Ge tandem solar cells were fabricated by a MOCVD technique.The photoelectric properties of the solar cells were characterized by a current-voltage test method.The dependence of the solar cell’s characteristics on temperature were investigated from 30 to 170°C at intervals of 20°C.Test results indicated that with increasing temperature,JSC of the cell increased slightly with a temperature coefficient of 9.8（μA/cm2）/°C.Voc reduced sharply with a coefficient of-5.6 mV/°C.FF was reduced with a temperature coefficient of—0.00063/℃. Furthermore,the conversion efficiency decreased linearly with increasing temperature which decreased from 28% at 30℃to 22.1%at 130°C.Also,detailed theoretical analyses for temperature characteristics of the solar cell were given.展开更多
文摘利用TFC光学膜系设计软件,设计出空间用GaInP/(In)GaAs/Ge三结太阳电池的分布式布拉格反射器(DBR)。由15对Al0.2Ga0.8As/Al0.9Ga0.1As组成的布拉格反射器在中心波长850 nm处反射率高达96%,可以使800~900 nm波段内红外光有效反射后被二次吸收,提高了Ga As子电池的抗辐照能力。通过对两种电池结构A、B地面模拟辐照试验获得1 Me V电子辐照下Ga In P/Ga As/Ge太阳电池电学参数随辐照注量退化的基本规律。在此基础上应用PC1D模拟程序分析太阳电池内部的载流子输运机理,建立1 Me V电子辐照下两种电池结构中多数载流子浓度和少数载流子扩散长度随辐照电子注量变化的基本规律。研究结果表明,多数载流子浓度和少数载流子扩散长度均随入射电子注量的增大而减小,同时原电池结构A中多数载流子去除率和少数载流子扩散长度损伤系数明显高于新电池结构B,由此表明包含布拉格反射器的新电池结构具有更强的抗辐照能力。
基金National Natural Science Foundation(61674013,51602022)Beijing Natural Science Foundation(2151004)Fundamental Research Funds for the Central Universities(2018QN054)
基金Supported by the Chinese Manned Spaceflight Programs and Chinese Space Agency
文摘Orbital experimental researches on crystal growth of Mn-doped GaSb and Bi2Se0.21Te2.79 are briefly summarized.The space experiments were completed in September of 2007 on broad the Foton-M3 satellite of Russia.Ground-based researches on the solidification behaviors of Al-Al3Ni,AlAl2Cu,Ag-Cu eutectic,Al-Pb monotectic and Cu-Co peritectic alloys in a 50-meter-high drop tube were investigated.New experimental results on the ultrasonic field and the temperature recycling induced to chiral symmetry breaking of NaClO3 crystal also were reported in the present paper.
文摘 The Engineering of Chinese Spacecraft provides Chinese scientists of materials great opportunity in the experiments for preparing materials under microgravity. On board of Spacecraft-Shenzhou No.3 (SZ-3), alloys and semiconductors, such as Al Mg2Si, Nd60Al10Fe20Co10, Pd40Ni10Cu30P20, Al-Al3Ni, GaMnSb, Bi12SiO20:Ce, and Cd0.96Zn0.04Te:Ge, were prepared. SZ-3 successfully returned to the earth on April 1, 2002. Profiting from SZ-3, great progress has been made in the researches on ma terials under microgravity in space. The quartz ampoules containing the materials grown on board of SZ-3 were shown in CFig. 1 (see the Appendix). The properties of the materials prepared on board of SZ-3 are still under investigation.……
基金This work was supported by the Special Fund for the Major State Basic Research Project (Grant No. G200(X)36505).
文摘CeO2 thin film was fabricated by dual ion beam epitaxial technique. The phenomenon of PL violet shift at room temperature was observed, and the distance of shift was about 65 nm. After the analysis of crystal structure and valence in the compound were carried out by XRD and XPS technique, it was concluded that the PL shift was related with valence of cerium ion in the oxides. When the valence of cerium ion varied from tetravalence to trivalence, the PL peak position would move from blue region to violet region and the phenomenon of 'violet shift' was observed.
基金This work was jointly supported by the Ministry of Chinese National Science and Technology (Grant No. PAN95-YU-34) Special Funds for Major State Basic Research Projects (Grant Nos. G20000683 and G20000365) the National Natural Science Foundation of
文摘A model for analyzing point defects in com-pound crystals was improved. Based on this modified model, a method for measuring Mn content in GaMnAs was estab-lished. A technique for eliminating the zero-drift-error was also established in the experiments of X-ray diffraction. With these methods, the Mn content in GaMnAs single crystals fabricated by the ion-beam epitaxy system was analyzed.
文摘GaInP/GaAs dual-junction solar cell with a conversion efficiency of 25.2% has been fabricated using metalorganic chemical vapor deposition (MOCVD) technique. Quantum efficiencies of the solar cell were measured within a temperature range from 25 to 160°C. The results indicate that the quantum efficiencies of the subcells increase slightly with the increasing temperature. And red-shift phenomena of absorption limit for all subcells are observed by increasing the cell’s work temperature, which are consistent with the viewpoint of energy gap narrowing effect. The short-circuit current density temperature coefficients dJ sc/dT of GaInP subcell and GaAs subcell are determined to be 8.9 and 7.4 μA/cm2/°C from the quantum efficiency data, respectively. And the open-circuit cell voltage temperature coefficients dV oc/dT calculated based on a theoretical equation are ?2.4 mV/°C and ?2.1 mV/°C for GaInP subcell and GaAs subcell.
基金supported by the National Natural Science Foundation of China (Grant Nos. 61006050 and 51072051)the Natural Science Foundation of Beijing,China (Grant No. 2102042)+2 种基金the Fundamental Research Funds for the Central Universities (Grant No. 10QG24)the National High Technology Research and Development Program ("863" Project)(Grant No. 2011AA050507)the National Basic Research Program of China("973" Project)(Grant No. 2010CB93380)
文摘Ag nanoparticles were fabricated on Si substrates by radio-frequency magnetron sputtering and thermal annealing treatments.It was found that Ag nanoparticles are ellipsoid at low annealing temperature,but the axis ratio decreases with the increase of annealing temperature,and a shape transformation from ellipsoid to sphere occurs when the temperature increases to a critical point.The experimental results showed that the surface plasmon resonances depend greatly on the nanoparticles'shape and size,which is in accordance with the theoretical calculation based on discrete dipole approximation.The results of forward-scattering efficiency(FSE) and light trapping spectrum(LTS) showed that Ag nanoparticles annealed at 400°C could strongly enhance the light harvest than those annealed at 300 and 500°C,and that the LTS peak intensity of the former is 1.7 and 1.5 times stronger than those of the later two samples,respectively.The conclusions obtained in this paper showed that Ag ellipsoid nanoparticles with appropriate size is more favorable for enhancing the light trapping.
基金This work was jointly supported by the Ministry of Chinese Science and Technology (Grant No. PAN95-YU-34), Special Funds for Major State Basic Research Projects (Grant Nos. G20000683 and G20000365), and the National Natural Science Foundation of China (
文摘Depth profiles of carrier concentrations in Ga-MnSb/GaSb are investigated by electrochemistry capacitance-voltage profiler and electrolyte of Tiron. The carrier concentration in GaMnSb/GaSb measured by this method is coincident with the results of Hall and X-ray diffraction measurements. It is indicated that most of the Mn atoms in GaMnSb take the site of Ga, play a role of acceptors, and provide shallow acceptor level(s).
基金supported by the National Basic Research Program of China ("973" Project) (Grant No 2010CB933803)the National Natural Science Foundation of China (Grant No 2102042)the Visiting Scholar Foundation of State Key Lab of Silicon Materials, Zhejiang Uni-versity ( Grant No SKL 2009-12)
文摘A polycrystalline silicon thin film was fabricated on glass substrate by means of aluminum induced crystallization (AIC). Al and α-Si layers were deposited by magnetron sputtering respectively and annealed at 480°C for 1 h to realize layer exchange. The polycrystalline silicon thin film was continuous and strongly (111) oriented. By analyzing the structure variation of the oxidation membrane and lattice mismatch between γ-Al2O3 and Si, it was concluded that aluminum promoted the formation of (111) oriented silicon nucleus by controlling the orientation of γ-Al2O3, which was formed at the early stage of annealing.
基金supported by the National Natural Science Foundation of China (50821004 and 61076051)the Program of Shanghai Subject Chief Scientist (09XD1404400)
文摘Previous reports about the thermal conductivities of VO2 showed various temperature dependences across metal-insulator transition (MIT) temperature. In this work, polycrystalline VO2 samples were fabricated by spark plasma sintering of VO2 powder. Temperature dependences of their thermal conductivities were investigated using laser flash technique, and the thermal conductivity showed a significant decrease trend from metal-phase to insulator phase. Electrical transport properties were investigated to confirm both carrier and lattice contribution to the thermal conductivity. It is found that the lattice thermal conductivity decreased significantly across MIT point, which may be caused by soft phonon mode in metal phase of VO2 .
基金supported by the National Natural Science Foundation of China (Grant Nos. 61006050, 20876040)the Natural Science Foundation of Beijing, China (Grant No. 2102042)+1 种基金the National Basic Research Program of China ("973" Project)(Grant No. 2010CB933800)the Fundamental Research Funds for the Central Universities (Grant No. 10QG24)
文摘A novel interconnected structure consisting of a conventional polyimide layer(PM) and an additional SiO2/TiAu/SiO2 sandwich multilayer has been firstly proposed for improving the performance of GaAs micro-solar cell array.The specific experimental investigations on the array with 108 unit cells have demonstrated that the novel structure of PM/SiO2/TiAu/SiO2 can effectively enhance the open-circuit voltage from 75 to 84 V and the fill factor from 35% to 57%.The performance improvement of our devices can be attributed to two aspects.Firstly,the TiAu shielding film can prevent the incident light from penetrating into the GaAs substrate so as to induce the serious substrate leakage current.Secondly,the compact texture of SiO2 in the novel structure can reduce the perimere recombination due to the crackle or shrinkage of PM.It is indicated that the novel structure can distinctly reduce the leakage current and improve output characteristic of micro-solar cells.
基金supported by Doctoral Initial Fund of Be ijing University of Technology,China(No.X0006015201101)the National Natural Foundation of China(No.10804005)
文摘GalnP/GaAs/Ge tandem solar cells were fabricated by a MOCVD technique.The photoelectric properties of the solar cells were characterized by a current-voltage test method.The dependence of the solar cell’s characteristics on temperature were investigated from 30 to 170°C at intervals of 20°C.Test results indicated that with increasing temperature,JSC of the cell increased slightly with a temperature coefficient of 9.8（μA/cm2）/°C.Voc reduced sharply with a coefficient of-5.6 mV/°C.FF was reduced with a temperature coefficient of—0.00063/℃. Furthermore,the conversion efficiency decreased linearly with increasing temperature which decreased from 28% at 30℃to 22.1%at 130°C.Also,detailed theoretical analyses for temperature characteristics of the solar cell were given.
