n-AlGaAs/GaAs-AlGaAs Double Quantum Wells with an AlAs Barrier: Relating the Cladding Doping Level to Structural and Transport Properties

摘要

Double quantum wells in the form of an AlGaAs/GaAs/AlGaAs heterostructure with an AlAs barrier a few monolayers thick are fabricated by MBE. Their structural and compositional characterization is carried out by double-crystal XRD and SIMS. Electron mobility is evaluated by Hall-effect measurements for different quantum-well thicknesses. Conditions are identified under which electron mobility can be enhanced by introduction of an ultrathin barrier into a single quantum well. The findings are analyzed from the viewpoint of interface structural quality.