Institute of Physics of National Academy of Sciences
of Azerbaidzhan
The paper is received on January 13, 2015
Abstract. The study of dielectric properties of
layer TlGaSe2 single crystal in frequency range f = 5´104–3.5´107 Hz allowed
to establish relaxation character of dispersion of dielectric permittivity and
nature of dielectric losses. It was shown that frequency dependence of the
dissipation factor tan δ is determined by the relaxation
polarization. The relaxation frequency fr = 8.8´105 Hz and
relaxation time τr = 1.1´10-6 s have
been estimated for TlGaSe2. The ac-conductivity across the
layers of studied crystals varies with frequency as σac~ f 0.8 which is
characteristic for hopping conductivity near the Fermi-level states. Density of
localized states at Fermi level NF = 7.5´1018 eV–1·cm–3,
the energy spread of these states ∆E = 5´10-3 eV,
average hopping time τ = 1.2´10–6 s and
distance R = 240 Å have been evaluated for TlGaSe2 single
crystal.
Keywords: single crystal, dielectric
permittivity, frequency, dielectric losses, hopping conductivity, relaxation
time, density of localized states.