Determination of Vibrational Eigenfrequencies of Semiconductors Using Tight-Binding Total Energy Calculations
J. Stephan and D. Suisky
Institut f├╝r Physik, Humboldt-Universit├Ąt zu Berlin, Invalidenstr. 110, 10115 Berlin, Germany
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We calculate the eigenfrequencies of bulk semiconductors using tight-binding total energy calculations of an ideal and a distorted lattice. We correlate the obtained energy change with the harmonic force constants appearing as parameters in the expansion of the potential energy of the crystal lattice in terms of the displacement. A good agreement of the calculated q = 0 optical vibrational modes with the experimental values for Si, Ge, GaAs and GaP bulk crystals is obtained. The influence of a surface on the force constants and the vibrational frequencies is studied.
DOI: 10.12693/APhysPolA.90.1075
PACS numbers: 63.20.-e