Title

Time-dependent density-functional approach for exciton binding energies

Authors

Authors

V. Turkowski; A. Leonardo;C. A. Ullrich

Comments

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Abbreviated Journal Title

Phys. Rev. B

Keywords

COEFFICIENT; CRYSTALS; LIFETIME; SYSTEMS; CDS; Physics, Condensed Matter

Abstract

Optical processes in insulators and semiconductors, including excitonic effects, can be described in principle exactly using time-dependent density-functional theory (TDDFT). Starting from a linearization of the TDDFT semiconductor Bloch equations in a two-band model, we derive a simple formalism for calculating exciton binding energies. This formalism leads to a generalization of the standard Wannier equation for excitons, featuring a nonlocal effective electron-hole interaction determined by long-range and dynamical exchange-correlation (XC) effects. We calculate exciton binding energies in several direct-gap semiconductors using exchange-only and model XC kernels.

Journal Title

Physical Review B

Volume

79

Issue/Number

23

Publication Date

1-1-2009

Document Type

Article

Language

English

First Page

4

WOS Identifier

WOS:000267699500008

ISSN

1098-0121

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