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Title: Observation of core-level binding energy shifts between (100) surface and bulk atoms of epitaxial CuInSe{sub 2}

Core-level and valence band photoemission from semiconductors has been shown to exhibit binding energy differences between surface atoms and bulk atoms, thus allowing one to unambiguously distinguish between the two atomic positions. Quite clearly, surface atoms experience a potential different from the bulk due to the lower coordination number - a characteristic feature of any surface is the incomplete atomic coordination. Theoretical accounts of this phenomena are well documented in the literature for III-V and II-VI semiconductors. However, surface state energies corresponding to the equilibrium geometry of (100) and (111) surfaces of Cu-based ternary chalcopyrite semiconductors have not been calculated or experimental determined. These compounds are generating great interest for optoelectronic and photovoltaic applications, and are an isoelectronic analog of the II-VI binary compound semiconductors. Surface core-level binding energy shifts depend on the surface cohesive energies, and surface cohesive energies are related to surface structure. For ternary compound semiconductor surfaces, such as CuInSe{sub 2}, one has the possibility of variations in surface stoichiometry. Applying standard thermodynamical calculations which consider the number of individual surface atoms and their respective chemical potentials should allow one to qualitatively determine the magnitude of surface core-level shifts and, consequently, surface state energies.
Authors:
 [1] ; ;  [2]
  1. Colorado School of Mines, Golden, CO (United States)
  2. Univ. of Illinois, Urbana-Champaign, IL (United States) [and others
Publication Date:
OSTI Identifier:
603574
Report Number(s):
LBNL--39981
ON: DE97007345; TRN: 98:009556
DOE Contract Number:
AC03-76SF00098
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Apr 1997; Related Information: Is Part Of Advanced light source: Compendium of user abstracts 1993--1996; PB: 622 p.
Research Org:
Lawrence Berkeley Lab., CA (United States)
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; INDIUM SELENIDES; COPPER SELENIDES; INNER-SHELL EXCITATION; BINDING ENERGY; SPECTRAL SHIFT; SURFACE PROPERTIES