ZnTe/GaAs(211)B heterojunction valence band discontinuity measured by X-ray photoelectron spectroscopy

Abstract

a b s t r a c tThin ZnTe layers were grown by molecular beam epitaxy on single crystal GaAs(2 1 1)B substrates. Reflection high energy electron diffraction monitored the deoxidation of substrate and entire growth process. Valence band offset was calculated with X-ray photoelectron spectroscopy. Also interface formation of the ZnTe/GaAs was studied. Analysis shows that interface is abrupt and calculated valance band offset is 0.25 ± 0.1 eV and indicates type I alignment. The experimental result agrees well with the theoretical predictions involving interface dipole effect as well as electron affinity rule.

Growth and characterization of CdTe absorbers on GaAs by MBE for high concentration PV solar cells

“…1). (211) surface orientation plays an important role to suppress twining and other structural defects during the growth of the CdTe absorbers [7]. Ideal epitaxial (211) layers grow on GaAs(211)B substrates with ~3 o tilting towards [-111] azimuth which allows a better lattice parameter match between the (4-2-2) planes of the CdTe and GaAs [8].…”