Interfacial chemistry of metals on CdTe and ZnTe (110)

We consider interfacial chemistry and band bending behavior for Al, In, Ag, and Pt overlayers on vacuum‐cleaved p‐CdTe and p‐ZnTe (110) in a comparative study using ultraviolet photoelectron spectroscopy and x‐ray photoelectron spectroscopy. A range of metal–substrate reactivities have been considered: Al reacts strongly with Te, Ag moderately, and In minimally, with no evidence seen for In reaction on ZnTe. Pt exhibits strong alloying behavior with both Cd and Zn. These results for the binaries are compared to metal/HgCdTe interface formation. We find that Hg loss can significantly influence the extent of reaction and/or intermixing for these overlayers, with resulting disruption either inhibiting or facilitating chemical interaction. Reaction and intermixing for Al, Ag, and Pt overlayers on CdTe and ZnTe indicate these interfaces are not ideal. The possible role of defects at these four metal/CdTe and metal/ZnTe interfaces is considered, and provides a consistent explanation for the final Fermi level po...