Binding energies of excitons in GaAs films on AlxGal-xAs substrates are studied theoretically with the fractional- dimensional approach. In this approach, the real anisotropic ＂exciton ＋ film＂ semiconductor system ...Binding energies of excitons in GaAs films on AlxGal-xAs substrates are studied theoretically with the fractional- dimensional approach. In this approach, the real anisotropic ＂exciton ＋ film＂ semiconductor system is mapped into an effective fractional-dimensional isotropic space. For different aluminum concentrations and substrate thicknesses, the exci- ton binding energies are obtained as a function of the film thickness. The numerical results show that, for different aluminum concentrations and substrate thicknesses, the exciton binding energies in GaAs films on AlxGal_xAs substrates all exhibit their maxima with increasing film thickness. It is also shown that the binding energies of heavy-hole and light-hole excitons both have their maxima with increasing film thickness.展开更多
The binding energy and effective mass of a polaron confined in a GaAs film deposited on an AlGal-xAs substrate are investigated, for different film thickness values and aluminum concentra- tions and within the framewo...The binding energy and effective mass of a polaron confined in a GaAs film deposited on an AlGal-xAs substrate are investigated, for different film thickness values and aluminum concentra- tions and within the framework of the fractional-dimensional space approach. Using this scheme, we propose a new method to define the effective length of the quantum confinement. The limita- tions of the definition of the original effective well width are discussed, and the binding energy and effective mass of a polaron confined in a GaAs film are obtained. The fl-actional-dimensional theo- retical results are shown to be in good agreement with previous, more detailed calculations based on second-order perturbation theory.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11304011)the Fundamental Research Funds for the Central Universitie China
文摘Binding energies of excitons in GaAs films on AlxGal-xAs substrates are studied theoretically with the fractional- dimensional approach. In this approach, the real anisotropic ＂exciton ＋ film＂ semiconductor system is mapped into an effective fractional-dimensional isotropic space. For different aluminum concentrations and substrate thicknesses, the exci- ton binding energies are obtained as a function of the film thickness. The numerical results show that, for different aluminum concentrations and substrate thicknesses, the exciton binding energies in GaAs films on AlxGal_xAs substrates all exhibit their maxima with increasing film thickness. It is also shown that the binding energies of heavy-hole and light-hole excitons both have their maxima with increasing film thickness.
文摘The binding energy and effective mass of a polaron confined in a GaAs film deposited on an AlGal-xAs substrate are investigated, for different film thickness values and aluminum concentra- tions and within the framework of the fractional-dimensional space approach. Using this scheme, we propose a new method to define the effective length of the quantum confinement. The limita- tions of the definition of the original effective well width are discussed, and the binding energy and effective mass of a polaron confined in a GaAs film are obtained. The fl-actional-dimensional theo- retical results are shown to be in good agreement with previous, more detailed calculations based on second-order perturbation theory.
