ELECTRON ACCUMULATION AT THE n-ZnSe/n-GaAs INTERFACE

Evidence for electron accumulation in the ZnSe side of n-ZnSe/n-GaAs heterostructures is presented. An n-GaAs buffer layer, approximately 1 pm thick, grown with low 1015 electronic concentration on a semi-insulating (100) GaAs substrate is fully depleted of electrons when an additional epilayer of nZnSe is grown on top of it. The n-GaAs epilayer electron concentration is restored when the ZnSe is removed by selective etching. The corresponding conductance of the n-ZnSe decreases logarithmically with temperature, going over to activated conduction below 6 K due to strong localization, a characteristic of a