The good quality of 200 pairs of highly strained In_(0.24)GaAs/GaAs multi-quantum-well(MQW)structure is demonstrated by the x-ray diffraction and photoluminescence curves.Large-area modulators based on the pseudomorph...The good quality of 200 pairs of highly strained In_(0.24)GaAs/GaAs multi-quantum-well(MQW)structure is demonstrated by the x-ray diffraction and photoluminescence curves.Large-area modulators based on the pseudomorphic In_(0.24)GaAs/GaAs MQW are designed and fabricated successfully,where the diameters are not less than 3 mm and the working wavelength is extended to 1064 nm.The single pass modulation depth is demonstrated to be 0.34 at 1064 nm at a reverse voltage of 80 V.展开更多
In order to investigate the carrier redistribution mechanisms in InAs/GaAs self-assembled quantum dots,the photoluminescent energy peak shift is studied with increasing excitation power.Unusually for samples of relati...In order to investigate the carrier redistribution mechanisms in InAs/GaAs self-assembled quantum dots,the photoluminescent energy peak shift is studied with increasing excitation power.Unusually for samples of relatively low density,it is shown that the energy peak position could recover slowly after a fast redshift,associated with the increasing excitation power.A theoretical model is presented,which involves the Auger effect assisting carrier recapture as important mechanisms during the relaxation process.展开更多
We report the coherent resonant emission of the exciton state in a single InAs quantum dot,embedded in a planar optical microcavity.The quantum dot is excited by a laser beam from the cleaved sample edge,and the reson...We report the coherent resonant emission of the exciton state in a single InAs quantum dot,embedded in a planar optical microcavity.The quantum dot is excited by a laser beam from the cleaved sample edge,and the resonant fluorescence is collected in the direction perpendicular to the excitation laser beam,so the residual laser scattering can be deeply suppressed.This experimental setup enables us to observe Rabi oscillation and a Mollow triplet with Rabi energy up to about 27μeV.展开更多
Tunable metamorphic InGaAs partially depleted absorber photodiodes with resonant cavity enhanced structure are fabricated on GaAs substrate.Dark-current densities of 7.2×10^(-7)A/cm^(2) at 0 V and 3.6×10^(-4...Tunable metamorphic InGaAs partially depleted absorber photodiodes with resonant cavity enhanced structure are fabricated on GaAs substrate.Dark-current densities of 7.2×10^(-7)A/cm^(2) at 0 V and 3.6×10^(-4)A/cm^(2) at-5 V,a high quantum efficiency of 74.4%at 1546nm,and a 3-dB bandwidth up to 12GHz are achieved.The full width at half maximum of the detector is about 16nm.Furthermore,through thermal tuning,the peak wavelength red shifts from 1527nm to 1544 nm,and a tuning range of 17nm is realized without fabricating extra tuning electrodes.展开更多
We report the fabrication of intermediate-band solar cells(IBSCs)based on quantum dots(QDs),which consists of a standard P-I-N structure with multilayer stacks of InAs/GaAs QDs in the I-layer.Compared with conventiona...We report the fabrication of intermediate-band solar cells(IBSCs)based on quantum dots(QDs),which consists of a standard P-I-N structure with multilayer stacks of InAs/GaAs QDs in the I-layer.Compared with conventional GaAs single-junction solar cells,the IBSCs based on InAs/GaAs QDs show a broader photo-response spectrum(>1330 nm),a higher short-circle current(about 53%increase)and a stronger radiation hardness.The results have important applications for realizing high efficiency solar cells with stronger radiation hardness.展开更多
According to the theory of optical films,we simulate the reflectivity of antireflection coatings(ARCS)for solar cells of Gao.51no.5P/GaAs/Ge based on an optical transfer matrix.In order to provide sufficient considera...According to the theory of optical films,we simulate the reflectivity of antireflection coatings(ARCS)for solar cells of Gao.51no.5P/GaAs/Ge based on an optical transfer matrix.In order to provide sufficient consideration of the refractive index dispersion effect of multilayer ARCS,we use multi-dimensional matrix data for reliable simulation.After the reflection curves are obtained,the effective average reflectance Re is introduced to optimize the film system by minimizing Re.Optimization of single layer(A1_(2)0_(3)),double layer(MgF_(2)/ZnS)and triple layer(MgF_(2)/A1_(2)0_(3)/ZnS)ARCS is realized by using this method for space and terrestrial applications.Effects of these ARCS are compared after optimization.These theoretical parameters can be used to guide experiments.展开更多
Self-organized In_(0.5)Ga_(0.5) As/GaAs quantum island structure emitting at 1.35μm at room temperature has been successfully fabricated by molecular beam epitaxy via cycled(InAs)1/(GaAs)1 monolayer deposition method...Self-organized In_(0.5)Ga_(0.5) As/GaAs quantum island structure emitting at 1.35μm at room temperature has been successfully fabricated by molecular beam epitaxy via cycled(InAs)1/(GaAs)1 monolayer deposition method.Photoluminescence measurement shows that a very narrow linewidth of 19.2 meV at 300 K has been reached for the first time,indicating effective suppression of inhomogeneous broadening of optical emission from the In_(0.5)Ga_(0.5) As island structure due to indium segregation reduction by introducing an AlAs layer and the strain reduction by inserting an In0.2Ga0.8As layer overgrown on the top of islands.The mounds-like morphology of the islands elongated along the[1ī0]azimuth are observed by the atomic force microscopy measurement,which reveals the fact that strain in the islands is partially relaxed along the[1ī0]direction.Our results present important information for the fabrication of 1.3μm wavelength quantum dot devices.展开更多
基金Advanced Research Foundation of China(914xxx803-051xxx111)National Defense Advanced Research project(315xxxxx301)National Defense Innovation Program(48xx4).
基金Supported by the National Natural Science Foundation of China(61774130,11474248,61790581,51973070)the Ph.D.Pro⁃grams Foundation of Ministry of Education of China(20105303120002)National Key Technology Research and Development Program of the Ministry of Sci⁃ence and Technology of China(2018YFA0209101).
基金the National Natural Science Foundation of China under Grant Nos 61274069,61176053 and 61021003the National High-Technology Research and Development Program of China under Grant No 2012AA012202the National Basic Research Program of China under Grant Nos 2012CB933503 and 2013CB932904.
文摘The good quality of 200 pairs of highly strained In_(0.24)GaAs/GaAs multi-quantum-well(MQW)structure is demonstrated by the x-ray diffraction and photoluminescence curves.Large-area modulators based on the pseudomorphic In_(0.24)GaAs/GaAs MQW are designed and fabricated successfully,where the diameters are not less than 3 mm and the working wavelength is extended to 1064 nm.The single pass modulation depth is demonstrated to be 0.34 at 1064 nm at a reverse voltage of 80 V.
基金Supported by the National Basic Research Program of Chinathe National Natural Science Foundation of China under Grant Nos 60921091,10874162 and 10734060.
文摘In order to investigate the carrier redistribution mechanisms in InAs/GaAs self-assembled quantum dots,the photoluminescent energy peak shift is studied with increasing excitation power.Unusually for samples of relatively low density,it is shown that the energy peak position could recover slowly after a fast redshift,associated with the increasing excitation power.A theoretical model is presented,which involves the Auger effect assisting carrier recapture as important mechanisms during the relaxation process.
基金Supported by the National Natural Science Foundation of China under Grant Nos 90921015,11074246.
文摘We report the coherent resonant emission of the exciton state in a single InAs quantum dot,embedded in a planar optical microcavity.The quantum dot is excited by a laser beam from the cleaved sample edge,and the resonant fluorescence is collected in the direction perpendicular to the excitation laser beam,so the residual laser scattering can be deeply suppressed.This experimental setup enables us to observe Rabi oscillation and a Mollow triplet with Rabi energy up to about 27μeV.
基金Supported by the National Natural Science Foundation of China under Grant Nos 60876039 and 61176053the Hi-Tech Research and Development Program of China(863 Program)under Grant No 2009AA03Z404the National Basic Research Program of China(973 Program)under Grant No 2010CB327601.
文摘Tunable metamorphic InGaAs partially depleted absorber photodiodes with resonant cavity enhanced structure are fabricated on GaAs substrate.Dark-current densities of 7.2×10^(-7)A/cm^(2) at 0 V and 3.6×10^(-4)A/cm^(2) at-5 V,a high quantum efficiency of 74.4%at 1546nm,and a 3-dB bandwidth up to 12GHz are achieved.The full width at half maximum of the detector is about 16nm.Furthermore,through thermal tuning,the peak wavelength red shifts from 1527nm to 1544 nm,and a tuning range of 17nm is realized without fabricating extra tuning electrodes.
基金Supported by the One-Hundred Talents Program of Chinese Academy of Sciences,and the National Science Foundation of China under Grant Nos 60876033,61076050 and 61021003.
文摘We report the fabrication of intermediate-band solar cells(IBSCs)based on quantum dots(QDs),which consists of a standard P-I-N structure with multilayer stacks of InAs/GaAs QDs in the I-layer.Compared with conventional GaAs single-junction solar cells,the IBSCs based on InAs/GaAs QDs show a broader photo-response spectrum(>1330 nm),a higher short-circle current(about 53%increase)and a stronger radiation hardness.The results have important applications for realizing high efficiency solar cells with stronger radiation hardness.
基金Supported by the National Natural Science Foundation of China under Grant No 60625405the National Basic Research Program of China under Grant Nos 2007CB936304 and 2010CB327601the China Postdoctoral Science Foundation under Grant No 20080440507.
文摘According to the theory of optical films,we simulate the reflectivity of antireflection coatings(ARCS)for solar cells of Gao.51no.5P/GaAs/Ge based on an optical transfer matrix.In order to provide sufficient consideration of the refractive index dispersion effect of multilayer ARCS,we use multi-dimensional matrix data for reliable simulation.After the reflection curves are obtained,the effective average reflectance Re is introduced to optimize the film system by minimizing Re.Optimization of single layer(A1_(2)0_(3)),double layer(MgF_(2)/ZnS)and triple layer(MgF_(2)/A1_(2)0_(3)/ZnS)ARCS is realized by using this method for space and terrestrial applications.Effects of these ARCS are compared after optimization.These theoretical parameters can be used to guide experiments.
基金Supported by the National Natural Science Foundation of China under Grant Nos.69876036 and 19823001Hundred Talent Program of Chinese Academy of Sciences,and State Climbing Research Project.
文摘Self-organized In_(0.5)Ga_(0.5) As/GaAs quantum island structure emitting at 1.35μm at room temperature has been successfully fabricated by molecular beam epitaxy via cycled(InAs)1/(GaAs)1 monolayer deposition method.Photoluminescence measurement shows that a very narrow linewidth of 19.2 meV at 300 K has been reached for the first time,indicating effective suppression of inhomogeneous broadening of optical emission from the In_(0.5)Ga_(0.5) As island structure due to indium segregation reduction by introducing an AlAs layer and the strain reduction by inserting an In0.2Ga0.8As layer overgrown on the top of islands.The mounds-like morphology of the islands elongated along the[1ī0]azimuth are observed by the atomic force microscopy measurement,which reveals the fact that strain in the islands is partially relaxed along the[1ī0]direction.Our results present important information for the fabrication of 1.3μm wavelength quantum dot devices.
