The inability of a single-gap solar cell to absorb energies less than the band-gap energy is one of the intrinsic loss mechanisms which limit the conversion efficiency in photovoltaic devices. New approaches to “ultr...The inability of a single-gap solar cell to absorb energies less than the band-gap energy is one of the intrinsic loss mechanisms which limit the conversion efficiency in photovoltaic devices. New approaches to “ultra-high” efficiency solar cells include devices such as multiple quantum wells (QW) and superlattices (SL) systems in the intrinsic region of a p-i-n cell of wider band-gap energy (barrier or host) semiconductor. These configurations are intended to extend the absorption band beyond the single gap host cell semiconductor. A theoretical model has been developed to study the performance of the strain-balanced GaAsP/InGaAs/GaAs MQWSC, and GaAs/GaInNAs MQWSC or SLSC. Our results show that conversion efficiencies can be reached which have never been obtained before for a single-junction solar cell.展开更多
High frequency modeling of quantum-well(QW) laser diodes for optoelectronic integrated circuit(OEIC) design is discussed in this paper.Modeling of the intrinsic device and the extrinsic components is discussed by acco...High frequency modeling of quantum-well(QW) laser diodes for optoelectronic integrated circuit(OEIC) design is discussed in this paper.Modeling of the intrinsic device and the extrinsic components is discussed by accounting for important physical effects at both dc and high frequency.The concepts of equivalent circuits representing both intrinsic and extrinsic components in a QW laser diode are analyzed to obtain a physics-based high frequency model.The model is based on the physical rate equations,and is versatile in that it permits both small-and large-signal simulations to be performed.Several procedures of the high frequency model parameter extraction are also discussed.Emphasis here is placed on validating the model via a comparison of simulated results with measured data of the small-signal modulation response,obtained over a wide range of optical output powers.展开更多
采用单量子阱近似模型 ,对 In Ga N/ Ga N量子阱中的激子和电子在导带子带间跃迁的光吸收效应进行了理论分析和数值计算 .结果表明 ,In的含量对激子的能量影响较大 ,而量子阱宽度的变化也对激子的能量有着微调作用 ;导带中电子从基态至...采用单量子阱近似模型 ,对 In Ga N/ Ga N量子阱中的激子和电子在导带子带间跃迁的光吸收效应进行了理论分析和数值计算 .结果表明 ,In的含量对激子的能量影响较大 ,而量子阱宽度的变化也对激子的能量有着微调作用 ;导带中电子从基态至第一激发态跃迁的吸收峰比较明显 ;随着 In的含量增加 ,量子阱中的激子能量间隔增大 ,吸收谱线的峰值位置会发生蓝移 .展开更多
文摘The inability of a single-gap solar cell to absorb energies less than the band-gap energy is one of the intrinsic loss mechanisms which limit the conversion efficiency in photovoltaic devices. New approaches to “ultra-high” efficiency solar cells include devices such as multiple quantum wells (QW) and superlattices (SL) systems in the intrinsic region of a p-i-n cell of wider band-gap energy (barrier or host) semiconductor. These configurations are intended to extend the absorption band beyond the single gap host cell semiconductor. A theoretical model has been developed to study the performance of the strain-balanced GaAsP/InGaAs/GaAs MQWSC, and GaAs/GaInNAs MQWSC or SLSC. Our results show that conversion efficiencies can be reached which have never been obtained before for a single-junction solar cell.
基金Supported by the National Natural Science Foundation of China (Grant No.6053-6010)Program for New Century Excellent Talents
文摘High frequency modeling of quantum-well(QW) laser diodes for optoelectronic integrated circuit(OEIC) design is discussed in this paper.Modeling of the intrinsic device and the extrinsic components is discussed by accounting for important physical effects at both dc and high frequency.The concepts of equivalent circuits representing both intrinsic and extrinsic components in a QW laser diode are analyzed to obtain a physics-based high frequency model.The model is based on the physical rate equations,and is versatile in that it permits both small-and large-signal simulations to be performed.Several procedures of the high frequency model parameter extraction are also discussed.Emphasis here is placed on validating the model via a comparison of simulated results with measured data of the small-signal modulation response,obtained over a wide range of optical output powers.
