"JOURNAL OF RADIO ELECTRONICS"  N 8, 2011

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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.