ELECTRON-DISTRIBUTION AND ELECTRICAL-PROPERTIES OF INAS QUANTUM-WELLS

We have investigated the dependence of the electrical characteristics on the vertical electric fields in InAs/(AlxGa1-x)Sb double heterostru ctures by Hall effect measurements. By measuring the samples with diff erent upper barrier thicknesses, we have observed the mobility modulat ion in the (AlGa)Sb/InAs/AlSb heterostructures by effectively changing the surface electric field. The mobility modulation is attributed to the modulated scattering probability depending on the electron distrib ution in the quantum well due to the built-in surface electric field. The proportionality coefficient of the sheet carrier concentration aga inst inverse upper barrier thickness roughly corresponds to the potent ial difference between the Fermi energy in the InAs quantum well and t he surface pinning level of GaSb under flat-band conditions.