Excitonic and quasiparticle gaps in Si nanocrystals

Citation
C. Delerue et al., Excitonic and quasiparticle gaps in Si nanocrystals, PHYS REV L, 84(11), 2000, pp. 2457-2460
Citations number
23
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW LETTERS
ISSN journal
00319007 → ACNP
Volume
84
Issue
11
Year of publication
2000
Pages
2457 - 2460
Database
ISI
SICI code
0031-9007(20000313)84:11<2457:EAQGIS>2.0.ZU;2-E
Abstract
We present calculations of the one- and two-particle excitations in silicon nanocrystals. The one-particle properties are handled in the GW approximat ion, and the excitonic gap is obtained from the Bethe-Salpeter equation. We develop a tight binding version of these methods to treat clusters up to 2 75 atoms. The self-energy and Coulomb corrections almost exactly cancel eac h other for crystallites with radius larger than 0.6 nm. The result of this cancellation is that one-particle calculations give quite accurate values for the excitonic gap of crystallites in the most studied range of sizes.