Dielectric Constant in Zn_xHg_1–xSe Determined by Raman Scattering

Abstract

D i e l e c t r i c C o n s t a n t in Z n x H g l -x S e D e t e r m i n e d by R a m a n Scattering K. KUMAZAKI BYZnxHgl-xSe(ZnHgSe) is a narrow-gap semiconductor (NGS), it is a mixture of a semimetal HgSe and a wide-gap semiconductor ZnSe. The value of the fundamental energy gap of this material, with the zincblende structure in the whole range of composition x, varies with x continuously from -0.02 to 2.7 eV. Recently, TO

Peculiarities of the Lattice Dynamics of Cubic Mercury Chalcogenides

“…However, a broad structured band extending from 150 to 200 cm À1 is also observed above the TO frequency. Such a broad band was already observed and interpreted as resulting from a coupled plasmon±phonon mode [12,13]. The similarity of this structure in both the Fe and Co doped samples in spite of the large difference of the plasma frequency observed in IR spectra leads us to reject this interpretation.…”

“…In particular, the important role of a`resonance' mode resulting from a two-phonon excitation (TO±TA or LO±TA in L and/or X point of the Brillouin zone) was suggested in [5,6]. On the contrary, to our knowledge, only two papers have been published on the Raman scattering spectra of HgSe (obtained for oriented samples at room temperature) [12,13]. The author of these publications interpreted the observed structures of his spectra as a TO mode and plasmon-phonon L À and L modes.…”

“…Lattice dynamics for HgSe was investigated in the past by IR reflectivity [4,5,10,11], Raman scattering [12,13] and neutron scattering [2,3,14] measurements. It is always an n-type material with a high free electron concentration.…”