Theoretical and experimental investigations of the electronic structure for selectively delta -doped strained InxGa1-xAs/GaAs quantum wells.

The electronic structures of Si \ensuremath{\delta}-doped strained ${\mathrm{In}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As/GaAs quantum wells have been studied theoretically and compared with experiments. The emphasis has been on the comparison between well center-, edge-, and barrier-positioned \ensuremath{\delta}-doped layers. The highest achievable single-subband occupation decreases as the \ensuremath{\delta} sheet is moved away from the center to the edge and finally to the barrier, but the electron mobility increases at the same time. Photoluminescence data have been found shifted to lower energies than the predictions of a self-consistent Hartree calculation owing to many-body effects, which have been quantified here using both plasmon-pole and random-phase approximations.