COMPLEX DIELECTRIC PERMITTIVITY AND
AC CONDUCTIVITY OF
GaSe SINGLE CRYSTALS GROWN FROM THE GAS PHASE
S. N. Mustafaeva, M. M. Asadov
1
Institute of physics of National academy of
sciences of Azerbaidzhan, Baku
2
Institute of chemical problems of
National academy of sciences of Azerbaidzhan, Baku
Received
July 16, 2011
Abstract.
The
frequency dispersion of the real (ε) and imaginary (ε ")
components of the complex dielectric constant, dielectric loss tangent tan d (f) and
ac-conductivity (σac) of the obtained layered GaSe single crystals
have been studied in the frequency range f = 5 ´ 104-3.5
´ 107
Hz. It was found that in
the studied crystals a relaxation dispersion of ε and ε " takes
place. It is shown that the dielectric losses in GaSe
are caused by the relaxation polarization and pass-through conduction. In the
frequency range f = 105-3.5 ´ 107
Hz ac-conductivity of the crystal GaSe varies as σac ~ f 0.8,
typical for hopping charge transport mechanism between localized states near
the Fermi level. The Fermi- level density of states NF
= 1.3 ´ 1018 eV-1 ×cm-3 and
the spread of these states ΔE = 0.048 eV, the average time τ = 0.1 ms and distance
R = 197 Å of jumps, as well as the localization
radius a = 32 Å have been estimated.
Keywords:
dielectric
properties, frequency, ac-conductivity,
GaSe single crystal.