针对户外变化的太阳光谱对多结太阳电池的电流匹配及效率有较大影响的问题,使用SMARTS软件计算青海格尔木地区全年不同时刻的户外太阳光谱,研究高倍聚光下Ga In P/Ga In As/Ge三结太阳电池在格尔木地区户外的输出特性;通过改变三结太阳...针对户外变化的太阳光谱对多结太阳电池的电流匹配及效率有较大影响的问题,使用SMARTS软件计算青海格尔木地区全年不同时刻的户外太阳光谱,研究高倍聚光下Ga In P/Ga In As/Ge三结太阳电池在格尔木地区户外的输出特性;通过改变三结太阳电池各子电池的电流匹配,优化三结电池结构。结果表明:在不考虑聚光光学系统影响的情况下,中电池标准光谱响应电流比顶电池小5%的Ga In P/Ga In As/Ge三结太阳电池在格尔木地区全年输出的电量最大;而考虑特定光学系统的影响后,中电池标准光谱响应电流比顶电池小2.5%的Ga In P/Ga In As/Ge三结太阳电池在格尔木地区全年输出的电量最大。展开更多
Wet thermal annealing effects on the properties of TaN/HfO2/Ge metal-oxide-semiconductor （MOS） structures with and without a GeO2 passivation layer are investigated. The physical and the electrical properties are ch...Wet thermal annealing effects on the properties of TaN/HfO2/Ge metal-oxide-semiconductor （MOS） structures with and without a GeO2 passivation layer are investigated. The physical and the electrical properties are characterized by X-ray photoemission spectroscopy, high-resolution transmission electron microscopy, capacitance-voltage （C-V） and current-voltage characteristics. It is demonstrated that wet thermal annealing at relatively higher temperature such as 550 ℃ can lead to Ge incorporation in HfO2 and the partial crystallization of HfO2, which should be responsible for the serious degradation of the electrical characteristics of the TaN/HfO2/Ge MOS capacitors. However, wet thermal annealing at 400 ℃ can decrease the GeOx interlayer thickness at the HfO2/Ge interface, resulting in a significant reduction of the interface states and a smaller effective oxide thickness, along with the introduction of a positive charge in the dielectrics due to the hydrolyzable property of GeOx in the wet ambient. The pre-growth of a thin GeO2 passivation layer can effectively suppress the interface states and improve the C V characteristics for the as-prepared HfO2 gated Ge MOS capacitors, but it also dissembles the benefits of wet thermal annealing to a certain extent.展开更多
Metamorphic In0.55Ga0.45P/In0.06Ga0.94As/Ge triple-junction （3J-MM） solar cells are grown on Ge （100） sub- strates via metal organic chemical vapor deposition. Epi-structural analyses such as high resolution x-ray...Metamorphic In0.55Ga0.45P/In0.06Ga0.94As/Ge triple-junction （3J-MM） solar cells are grown on Ge （100） sub- strates via metal organic chemical vapor deposition. Epi-structural analyses such as high resolution x-ray diffrac- tion, photoluminence, cathodoluminescence and HRTEM are employed and the results show that the high crystal quality of 3J-MM solar cells is obtained with low threading dislocation density of graded buffer （an average value of 6.8× 10^4/cm2）. Benefitting from the optimized bandgap combination, under one sun, AM0 spectrum, 25℃ conditions, the conversion efficiency is achieved about 32%, 5% higher compared with the lattice-matched In0.49Ga0.51P/In0.01Ga0.99As/Ge triple junction （3J-LM） solar cell. Under 1-MeV electron irradiation test, the degradation of the EQE and I-V characteristics of 3J-MM solar cells is at the same level as the 33-LM solar cell. The end-of-life efficiency is -27.1%. Therefore, the metamorphic triple-junction solar cell may be a promising candidate for next-generation space multi-junction solar cells.展开更多
文摘针对户外变化的太阳光谱对多结太阳电池的电流匹配及效率有较大影响的问题,使用SMARTS软件计算青海格尔木地区全年不同时刻的户外太阳光谱,研究高倍聚光下Ga In P/Ga In As/Ge三结太阳电池在格尔木地区户外的输出特性;通过改变三结太阳电池各子电池的电流匹配,优化三结电池结构。结果表明:在不考虑聚光光学系统影响的情况下,中电池标准光谱响应电流比顶电池小5%的Ga In P/Ga In As/Ge三结太阳电池在格尔木地区全年输出的电量最大;而考虑特定光学系统的影响后,中电池标准光谱响应电流比顶电池小2.5%的Ga In P/Ga In As/Ge三结太阳电池在格尔木地区全年输出的电量最大。
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61176092,61036003,and 60837001)the National Basic Research Program of China (Grant No. 2012CB933503)+1 种基金the Ph.D. Program Foundation of Ministry of Education of China (Grant No. 20110121110025)the Fundamental Research Funds for the Central Universities,China (Grant No. 2010121056)
文摘Wet thermal annealing effects on the properties of TaN/HfO2/Ge metal-oxide-semiconductor （MOS） structures with and without a GeO2 passivation layer are investigated. The physical and the electrical properties are characterized by X-ray photoemission spectroscopy, high-resolution transmission electron microscopy, capacitance-voltage （C-V） and current-voltage characteristics. It is demonstrated that wet thermal annealing at relatively higher temperature such as 550 ℃ can lead to Ge incorporation in HfO2 and the partial crystallization of HfO2, which should be responsible for the serious degradation of the electrical characteristics of the TaN/HfO2/Ge MOS capacitors. However, wet thermal annealing at 400 ℃ can decrease the GeOx interlayer thickness at the HfO2/Ge interface, resulting in a significant reduction of the interface states and a smaller effective oxide thickness, along with the introduction of a positive charge in the dielectrics due to the hydrolyzable property of GeOx in the wet ambient. The pre-growth of a thin GeO2 passivation layer can effectively suppress the interface states and improve the C V characteristics for the as-prepared HfO2 gated Ge MOS capacitors, but it also dissembles the benefits of wet thermal annealing to a certain extent.
基金Supported by the Grand from Tianjin Little Giant Fund under Grant No 14ZXLJGX00400the Tianjin Science and Technology Support Plan under Grant No 16YFZCGX00030
文摘Metamorphic In0.55Ga0.45P/In0.06Ga0.94As/Ge triple-junction （3J-MM） solar cells are grown on Ge （100） sub- strates via metal organic chemical vapor deposition. Epi-structural analyses such as high resolution x-ray diffrac- tion, photoluminence, cathodoluminescence and HRTEM are employed and the results show that the high crystal quality of 3J-MM solar cells is obtained with low threading dislocation density of graded buffer （an average value of 6.8× 10^4/cm2）. Benefitting from the optimized bandgap combination, under one sun, AM0 spectrum, 25℃ conditions, the conversion efficiency is achieved about 32%, 5% higher compared with the lattice-matched In0.49Ga0.51P/In0.01Ga0.99As/Ge triple junction （3J-LM） solar cell. Under 1-MeV electron irradiation test, the degradation of the EQE and I-V characteristics of 3J-MM solar cells is at the same level as the 33-LM solar cell. The end-of-life efficiency is -27.1%. Therefore, the metamorphic triple-junction solar cell may be a promising candidate for next-generation space multi-junction solar cells.
