Electron mobilities in modulation-doped AlxGa1-xAs/GaAs and pseudomorphic AlxGa1-xAs/InyGa1-yAs quantum-well structures.

摘要: Electron mobilities in modulation-doped ${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As/GaAs/${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As and pseudomorphic ${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As/${\mathrm{In}}_{\mathit{y}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{y}}$As/${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As quantum-well structures with high electron concentration have been measured order to clarify their dependences on the thickness. It has found that 77-K show highest values for widths ranging from 80 100 \AA{}. To understand experimental results, mobility calculations were performed using a two-subband transport model. The of thickness reproduced theoretical it conditions at 77 K correspond case when Fermi energies electrons ground subband become maximum almost all populating subband. For wider thicknesses, begin populate upper subband, which results sudden reduction due increase intersubband scattering rate reductions