"JOURNAL OF RADIO ELECTRONICS"  N 1, 2015

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DISPERSION OF COMPLEX DIELECTRIC PERMITTIVITY AND CONDUCTIVITY OF  TlGaSe2  SINGLE CRYSTALS AT RADIO FREQUENCIES

 S. N. Mustafaeva

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.