The population of the third(n=3)two-dimensional electron subband of InGaAs/InAlAs modulation-doped structures has been observed by means of Fourier transform photoluminescence(PL).Three well resolved PL peaks centred ...The population of the third(n=3)two-dimensional electron subband of InGaAs/InAlAs modulation-doped structures has been observed by means of Fourier transform photoluminescence(PL).Three well resolved PL peaks centred at 0.737,0.908,and 0.980eV are observed,which are attributed to the transitions from the lowest three electron subbands to the n=1 heavy-hole subband.The subband separations clearly exhibiting the features of the stepped quantum well with triangle and square potentials are consistent with numerical calculation.Thanks to the presence of Fermi cutoff,the population ratio of these three subbands can be estimated.Temperature and excitation-dependent luminescences are also analyzed.展开更多
A 10-InAs-island-layer vertically coupled quantum dot structure on(001)GaAs was grown and investigated by molecular beam epitaxy and transmission electron microscopy.The result shows that the vertically aligned InAs i...A 10-InAs-island-layer vertically coupled quantum dot structure on(001)GaAs was grown and investigated by molecular beam epitaxy and transmission electron microscopy.The result shows that the vertically aligned InAs islands are asymmetrical along the two<110>directions on the(001)growth plane.Such an asymmetry in the vertically coupled quantum dot structure can be explained with the chemical polarity in the Ⅲ-Ⅳ compound semiconductors.展开更多
In-plane optical anisotropy which comes from the heavy hole and the light hole transitions in an InAs monolayer inserted in(311)-oriented GaAs matrix is observed by reflectance difference spectroscopy.The observed ste...In-plane optical anisotropy which comes from the heavy hole and the light hole transitions in an InAs monolayer inserted in(311)-oriented GaAs matrix is observed by reflectance difference spectroscopy.The observed steplike density of states demonstrates that the InAs layer behaves like a two-dimensional quantum well rather than isolated quantum dots.The magnitude of the anisotropy is in good agreement with the intrinsic anisotropy of(311)orientation quantum wells,indicating that there is little structural or strain anisotropy of the InAs layer grown on(311)-oriented GaAs surface.展开更多
基金Supported by the National Natural Science Foundation of China.
文摘The population of the third(n=3)two-dimensional electron subband of InGaAs/InAlAs modulation-doped structures has been observed by means of Fourier transform photoluminescence(PL).Three well resolved PL peaks centred at 0.737,0.908,and 0.980eV are observed,which are attributed to the transitions from the lowest three electron subbands to the n=1 heavy-hole subband.The subband separations clearly exhibiting the features of the stepped quantum well with triangle and square potentials are consistent with numerical calculation.Thanks to the presence of Fermi cutoff,the population ratio of these three subbands can be estimated.Temperature and excitation-dependent luminescences are also analyzed.
基金Supported by the National Natural Science Foundation of China under Grant No.69576026。
文摘A 10-InAs-island-layer vertically coupled quantum dot structure on(001)GaAs was grown and investigated by molecular beam epitaxy and transmission electron microscopy.The result shows that the vertically aligned InAs islands are asymmetrical along the two<110>directions on the(001)growth plane.Such an asymmetry in the vertically coupled quantum dot structure can be explained with the chemical polarity in the Ⅲ-Ⅳ compound semiconductors.
基金Supported by the National Natural Science Foundation of China under Grant No.F040105.
文摘In-plane optical anisotropy which comes from the heavy hole and the light hole transitions in an InAs monolayer inserted in(311)-oriented GaAs matrix is observed by reflectance difference spectroscopy.The observed steplike density of states demonstrates that the InAs layer behaves like a two-dimensional quantum well rather than isolated quantum dots.The magnitude of the anisotropy is in good agreement with the intrinsic anisotropy of(311)orientation quantum wells,indicating that there is little structural or strain anisotropy of the InAs layer grown on(311)-oriented GaAs surface.
