PROPERTIES OF II-VI/III-V HETEROVALENT INTERFACES

The paper addresses two issues related to II-VI/III-V heterostructures. The first topic is a discussion of the nature of the bonding at CdTe/InSb and ZnSe/GaAs interfaces grown by molecular beam epitaxy. The bonding is studied by means of in situ X-ray photoelectron spectroscopy (XPS). A comparison of the In 3d core level features from an InSb epilayer surface, a Te-reacted InSb surface, very thin (a few monolayers thick) CdTe/InSb epilayer/epilayer heterostructures and from deliberately grown (In,Te) epilayers, indicate that the Te-reacted layer, the CdTe/InSb heterostructures and the (In,Te) epilayers exhibit similar In bonding characteristics. A parallel XPS study of ZnSe/GaAs interfaces reinforces the conclusion that there is a general tendency for the formation of a III-VI interfacial compound when forming II-VI/III-V junctions. The second topic concerns a description of pn junction light emitting devices based on ZnSe. In the structures described, carriers are injected from nitrogen doped p-ZnSe and chlorine doped n-ZnSe into a multiple quantum well structure having (Zn,Cd)Se wells and ZnSe barriers. The bright CW photon emission originates from quantum well transitions.