PHOTOEMISSION-STUDY OF THE CDS/CDTE(110) INTERFACE

The formation and electronic interface properties of CdS grown by molecular beam epitaxy (MBE) on CdTe(110) substrates was studied by angle-resolved synchrotron radiation photomission spectroscopy (ARPES) and reflection high-energy electron diffraction (RHEED). Core level intensity measurements from the CdTe substrate as well as from the CdS overlayer indicate the epitaxial two-dimensional deposition of zinc blende CdS films, The analysis of core and valence band spectra of the heterostnicture shows that the interface is nonreactive and atomically abrupt. The CdS valence band is offset by ΔEv= — 0.65 eV with respect to the Γ15vpoint of CdTe. Using the band gap of cubic CdS, which is close to that of the thermodynamic stable wurtzite structured CdS of Eg= 2.42 eV, the conduction band offset at the CdS/ CdTe(110) interface is determined to be ΔEc= 0.21 eV. © 1990, American Vacuum Society. All rights reserved.