A photovoltaic quantum dot infrared photodetector with InAs/GaAs/AIGaAs structures is reported. The detector is sensitive to normal incident light. At zero bias and 78K, a clear spectral response in the range of 2-7μ...A photovoltaic quantum dot infrared photodetector with InAs/GaAs/AIGaAs structures is reported. The detector is sensitive to normal incident light. At zero bias and 78K, a clear spectral response in the range of 2-7μm has been obtained with peaks at 3.1, 4.8 and 5.7μm. The bandgap energies of GaAs and Al0.2Ga0.8As at 78K are calculated and the energy diagram of the transitions in the Quantum-Dot Infrared Photodetector （QDIP） is given out. The photocurrent signals can be detected up to 110 K, which is state-of-the-art for photovoltaic QDIP, The photovoltaic effect in our detector is a result of the enhanced band asymmetry as we design in the structure.展开更多
Room temperature,continuous-wave bistable operation is achieved in two-section 1.24μm InAs quantum-dot （QD） lasers with integrated intracavity QD saturable absorbers（SA）.It is found that the hysteresis width is n...Room temperature,continuous-wave bistable operation is achieved in two-section 1.24μm InAs quantum-dot （QD） lasers with integrated intracavity QD saturable absorbers（SA）.It is found that the hysteresis width is narrowed with increasing reverse bias voltage,and broadened with increasing length of saturable absorber.This can be explained by the competition between QD absorption and electroabsorption in the SA section.In addition,a larger hysteresis width is realized than other reports so far,which can be attributed to a greater number of stacked layers of active region in our case.The experimental results can be explained by a modified threshold current model.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 60990315 and 60676029, and the National Basic Research Program No 2006CB604904.
文摘A photovoltaic quantum dot infrared photodetector with InAs/GaAs/AIGaAs structures is reported. The detector is sensitive to normal incident light. At zero bias and 78K, a clear spectral response in the range of 2-7μm has been obtained with peaks at 3.1, 4.8 and 5.7μm. The bandgap energies of GaAs and Al0.2Ga0.8As at 78K are calculated and the energy diagram of the transitions in the Quantum-Dot Infrared Photodetector （QDIP） is given out. The photocurrent signals can be detected up to 110 K, which is state-of-the-art for photovoltaic QDIP, The photovoltaic effect in our detector is a result of the enhanced band asymmetry as we design in the structure.
文摘Room temperature,continuous-wave bistable operation is achieved in two-section 1.24μm InAs quantum-dot （QD） lasers with integrated intracavity QD saturable absorbers（SA）.It is found that the hysteresis width is narrowed with increasing reverse bias voltage,and broadened with increasing length of saturable absorber.This can be explained by the competition between QD absorption and electroabsorption in the SA section.In addition,a larger hysteresis width is realized than other reports so far,which can be attributed to a greater number of stacked layers of active region in our case.The experimental results can be explained by a modified threshold current model.
