Time-dependent density-functional approach for exciton binding energies

    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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