Laser photovoltaic devices converting 1064 nm light energy into electric energy present a promising prospect in wireless energy transmission due to the commercial availability of high power 1064 nm lasers with very sm...Laser photovoltaic devices converting 1064 nm light energy into electric energy present a promising prospect in wireless energy transmission due to the commercial availability of high power 1064 nm lasers with very small divergence. Besides their high conversion efficiency, a high output voltage is also expected in a laser energy transmission system. Meanwhile,1064 nm InGaAsP multi-junction laser power converters have been developed using p^+-InGaAs/n^+-InGaAs tunnel junctions to connect sub-cells in series to obtain a high output voltage. The triple-junction laser power converter structures are grown on p-type InP substrates by metal-organic chemical vapor deposition(MOCVD), and InGaAsP laser power converters are fabricated by conventional photovoltaic device processing. The room-temperature I–V measurements show that the 1 × 1 cm^2 triplejunction InGaAsP laser power converters demonstrate a conversion efficiency of 32.6% at a power density of 1.1 W/cm^2, with an open-circuit voltage of 2.16 V and a fill factor of 0.74. In this paper, the characteristics of the laser power converters are analyzed and ways to improve the conversion efficiency are discussed.展开更多
We report our progress in the high-temperature superconductor(HTS)Josephson junction fabrication process founded on utilizing a focused helium ion beam damaging technique and discuss the expected device performance at...We report our progress in the high-temperature superconductor(HTS)Josephson junction fabrication process founded on utilizing a focused helium ion beam damaging technique and discuss the expected device performance attainable with the HTS multi-junction device technology.Both the achievable high value of characteristic voltage V_(C)=I_(C)R_(N)of Josephson junctions and the ability to design a large number of arbitrary located Josephson junctions allow narrowing the existing gap in design abilities for lowtemperature superconductor(LTS)and HTS circuits even with using a single YBa_(2)Cu_(3)O_(7-x) film layer.A one-layer topology of active electrically small antenna is suggested and its voltage response characteristics are considered.展开更多
A metamorphic GaInP/GaAs/GaInAs/Ge multi-junction solar cell with InAs quantum dots is investigated, and the analytical expression of the energy conversion efficiency on the multi-junction tandem solar cell is derived...A metamorphic GaInP/GaAs/GaInAs/Ge multi-junction solar cell with InAs quantum dots is investigated, and the analytical expression of the energy conversion efficiency on the multi-junction tandem solar cell is derived using the detailed balance principle and the Kronig-Penney model.The influences of interdot distance, quantum-dot size and the intermediate band location on the energy conversion efficiency are studied.This shows that the maximum efficiency,as a function of quantum-dot size and distance,is about 60.15%under the maximum concentration for only one InAs/GaAs subcell,and is even up to 39.69%for the overall cell.In addition,other efficiency factors such as current mismatch,the formation of a quasicontinuum conduction band and concentrated light are examined.展开更多
为了解决接轨站选择中定性描述多、比选方案数量庞大、比选机制主观性强的难题,首先对定性因素进行客观量化分析,然后构建考虑多新建车站位置的多目标整数规划模型,其次,基于Pareto最优解原理,结合线性逼近的约束优化算法和分支定界算...为了解决接轨站选择中定性描述多、比选方案数量庞大、比选机制主观性强的难题,首先对定性因素进行客观量化分析,然后构建考虑多新建车站位置的多目标整数规划模型,其次,基于Pareto最优解原理,结合线性逼近的约束优化算法和分支定界算法的基本原理,设计模型的求解算法,最后,以新建济南至枣庄铁路项目为工程实例对模型与算法进行验证并将计算结果与人工比选结果相比较,得出结论:模型推荐的最终方案以增加0.2%的少量建造成本为代价,分别提升可及性4.65%、路网运输能力1.35%,同时计算时间仅为4 min 20 s,而人工比选需要花费大量的人力、物力、时间用于计算。以上对比证实该模型不仅能得出优于或等于人工比选的最终结果,同时还能节省大量人力物力以及工作时间,具有理论和工程应用价值。展开更多
基金partially supported by the Jiangsu Province Science Foundation for Youths (No. BK20170431)the National Natural Science Foundation of China (No. 61604171)。
文摘Laser photovoltaic devices converting 1064 nm light energy into electric energy present a promising prospect in wireless energy transmission due to the commercial availability of high power 1064 nm lasers with very small divergence. Besides their high conversion efficiency, a high output voltage is also expected in a laser energy transmission system. Meanwhile,1064 nm InGaAsP multi-junction laser power converters have been developed using p^+-InGaAs/n^+-InGaAs tunnel junctions to connect sub-cells in series to obtain a high output voltage. The triple-junction laser power converter structures are grown on p-type InP substrates by metal-organic chemical vapor deposition(MOCVD), and InGaAsP laser power converters are fabricated by conventional photovoltaic device processing. The room-temperature I–V measurements show that the 1 × 1 cm^2 triplejunction InGaAsP laser power converters demonstrate a conversion efficiency of 32.6% at a power density of 1.1 W/cm^2, with an open-circuit voltage of 2.16 V and a fill factor of 0.74. In this paper, the characteristics of the laser power converters are analyzed and ways to improve the conversion efficiency are discussed.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1603900)in part by the Russian Science Foundation(RSCF)(Grant No.19-72-10016-P).
文摘We report our progress in the high-temperature superconductor(HTS)Josephson junction fabrication process founded on utilizing a focused helium ion beam damaging technique and discuss the expected device performance attainable with the HTS multi-junction device technology.Both the achievable high value of characteristic voltage V_(C)=I_(C)R_(N)of Josephson junctions and the ability to design a large number of arbitrary located Josephson junctions allow narrowing the existing gap in design abilities for lowtemperature superconductor(LTS)and HTS circuits even with using a single YBa_(2)Cu_(3)O_(7-x) film layer.A one-layer topology of active electrically small antenna is suggested and its voltage response characteristics are considered.
文摘A metamorphic GaInP/GaAs/GaInAs/Ge multi-junction solar cell with InAs quantum dots is investigated, and the analytical expression of the energy conversion efficiency on the multi-junction tandem solar cell is derived using the detailed balance principle and the Kronig-Penney model.The influences of interdot distance, quantum-dot size and the intermediate band location on the energy conversion efficiency are studied.This shows that the maximum efficiency,as a function of quantum-dot size and distance,is about 60.15%under the maximum concentration for only one InAs/GaAs subcell,and is even up to 39.69%for the overall cell.In addition,other efficiency factors such as current mismatch,the formation of a quasicontinuum conduction band and concentrated light are examined.
文摘为了解决接轨站选择中定性描述多、比选方案数量庞大、比选机制主观性强的难题,首先对定性因素进行客观量化分析,然后构建考虑多新建车站位置的多目标整数规划模型,其次,基于Pareto最优解原理,结合线性逼近的约束优化算法和分支定界算法的基本原理,设计模型的求解算法,最后,以新建济南至枣庄铁路项目为工程实例对模型与算法进行验证并将计算结果与人工比选结果相比较,得出结论:模型推荐的最终方案以增加0.2%的少量建造成本为代价,分别提升可及性4.65%、路网运输能力1.35%,同时计算时间仅为4 min 20 s,而人工比选需要花费大量的人力、物力、时间用于计算。以上对比证实该模型不仅能得出优于或等于人工比选的最终结果,同时还能节省大量人力物力以及工作时间,具有理论和工程应用价值。
