Accurate theory of excitons in GaAs-Ga1-xAlxAs quantum wells.

摘要: Binding energies of excitons in quantum wells are calculated including valence-band mixing and also other important effects, namely Coulomb coupling between belonging to different subbands (which is predominantly with the exciton continuum), nonparabolicity bulk conduction band, difference dielectric constants well barrier materials. All these effects found be a comparable size, tend increase binding energies, taken together result very high particularly narrow GaAs/AlAs wells. can even higher than two-dimensional limit four times Rydberg. Theoretical results agree within few tenths milli-electron-volt available photoluminescence excitation experiments. Valence-band gives finite oscillator strength some not s states, but does change selection rules based on parity. Calculated strengths ground-state heavy- light-hole good agreement absorption reflectivity