OHMIC CONTACTS AND TRANSPORT-PROPERTIES IN ZNSE-BASED HETEROSTRUCTURES

In this paper both horizontal and vertical transport properties of ZnS e based heterostructures were studied. Temperature-dependent Hall effe ct measurements were performed on nitrogen-doped ZnSe, ZnTe, Zn(S,Se) and (Zn,Mg)(S,Se) epilayers; accepter concentration N(a), compensation donor concentration N(d) and the activation energy E(a) were derived by curve-fitting to the freeze-out behavior of the hole concentrations . Vertical transport study, through the use of an analytical computer simulation, suggested that the electron transport across the n-ZnSe/n- GaAs heterointerface is often hindered by the presence of a high densi ty of interface states; both the employment of heavy doping near the i nterface and the modification of GaAs surface stoichiometry before the nucleation of ZnSe were found effective in reducing the device impeda nce.