https://doi.org/10.1140/epjb/e2004-00164-3
Structural, electronic, and optical properties of beryllium monochalcogenides
Department of Physics and Astronomy, University of Nigeria, Nsukka, Nigeria
Corresponding author: a okoyecmi@yahoo.com
Received:
26
September
2003
Published online:
18
June
2004
The results of first-principles theoretical study of the structural, electronic and optical
properties of beryllium monochalcogenides BeTe, BeSe and BeS, performed using the full potential
linearized augmented plane wave (FP-LAPW) method are presented. The calculated structural parameters
and band gaps compare very well with previous theoretical results. The trends of the band gap
pressure coefficients and volume deformation potentials for these II-VI compounds
are investigated. The linear pressure
coefficients for the 
X and 
band gaps increase with decrease in anion atomic weight. The
dependence of the direct and indirect band gaps on the relative change of lattice constant
are found to follow almost the same type of trends in each of these compounds. The volume deformation potential (
) for
the direct (
) and indirect (
) gaps are positive, but negative for the indirect
(
) gap. Furthermore, , for 
transitions
decreases with increase in anion atomic number whereas 
, increases. The optical
properties have also been calculated. From the reflectivity spectra, the compounds will be useful for optical
applications. The variation of the band gaps with respect to the application of pressure and the origin of some of
the peaks in the optical spectra are discussed in terms the calculated electronic structure.
PACS: 71.15.Ap – Basis sets (LCAO, plane-wave, APW, etc.) and related methodology (scattering methods, ASA, linearized methods, etc.) / 71.15.Mb – Density functional theory, local density approximation, gradient and other corrections / 71.20.Nr – Semiconductor compounds
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004
