Phys. Rev. Lett. 79, 1770–1773 (1997)Quantum Confinement and Optical Gaps in Si NanocrystalsReceived 20 May 1997; published in the issue dated 1 September 1997 Quasiparticle gaps, self-energy corrections, exciton Coulomb energies, and optical gaps in Si quantum dots are calculated from first principles using a real-space pseudopotential method. The calculations are performed on hydrogen-passivated spherical Si clusters with diameters up to 27.2 Å ( ∼800Si and H atoms). It is shown that (i) the self-energy correction in quantum dots is enhanced substantially compared to bulk, and is not size independent as implicitly assumed in all semiempirical calculations, and (ii) quantum confinement and reduced electronic screening result in appreciable excitonic Coulomb energies. Calculated optical gaps are in very good agreement with absorption data. © 1997 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevLett.79.1770
DOI:
10.1103/PhysRevLett.79.1770
PACS:
78.66.Db, 61.46.+w, 71.35.Cc, 73.20.Dx
See AlsoComment: R. W. Godby and I. D. White, Density-Relaxation Part of the Self-Energy, Phys. Rev. Lett. 80, 3161 (1998). Comment: A. Franceschetti, L. W. Wang, and A. Zunger, Comment on “Quantum Confinement and Optical Gaps in Si Nanocrystals”, Phys. Rev. Lett. 83, 1269 (1999). Reply: Serdar Öğüt, James R. Chelikowsky, and Steven G. Louie, Öğüt, Chelikowsky, and Louie Reply:, Phys. Rev. Lett. 80, 3162 (1998). Reply: Serdar Öğüt, James R. Chelikowsky, and Steven G. Louie, Öğüt, Chelikowsky, and Louie Reply:, Phys. Rev. Lett. 83, 1270 (1999). |
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