Excitons and Optical Spectrum of the Si(111)- (2{times}1) Surface

Journal Article · Thu Jul 01 04:00:00 EDT 1999 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.83.856· OSTI ID:357317

Rohlfing, M ^[1]; Louie, S G ^[2]

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1. Institut fuer Theoretische Physik II--Festkoerperphysik, Universitaet Muenster, Wilhelm-Klemm-Strasse 10, 48149 Muenster (Germany)
2. Department of Physics, University of California, Berkeley, California 94720-7300 (United States)

We investigate excitons at the Si(111)-( 2{times}1) surface and their optical spectrum from first principles. This is done by solving the Bethe-Salpeter equation for the two-particle Green`s function, including the electron-hole interaction. The optical spectrum of the surface is dominated by a surface exciton formed from the {pi} -bonded surface states. The excitonic binding energy is more than 1thinspthinsporder of magnitude larger than in bulk Si. The two-particle wave function of the exciton state is strongly localized at the surface and exhibits distinct anisotropy due to the surface reconstruction. {copyright} {ital 1999} {ital The American Physical Society }

• Research Organization: Lawrence Berkeley National Laboratory
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 357317
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 4 Vol. 83; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANISOTROPY
BINDING ENERGY
ELECTRON CORRELATION
ELECTRON-HOLE COUPLING
EXCITONS
GREEN FUNCTION
SILICON
SURFACE PROPERTIES
WAVE FUNCTIONS