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Semiconductor Physics, Quantum Electronics & Optoelectronics. 2007. V. 10, N 2. P. 058-061.
Frequency-dependent dielectric coefficients
of TlInS2 amorphous films
1Institute of Physics, Azerbaijan National Academy of Sciences
Abstract. The frequency dispersion of the loss tangent (tgδ) and the ac conductivity (σ ac )
of amorphous films prepared by evaporation of TlInS 2 has been investigated at
frequencies f = 5⋅10 4 …3.5⋅10 7 Hz. It is shown that, at f > 10 6 Hz, relaxation losses take
place. It is established that the hopping conduction near the Fermi level occurs in TlInS 2
amorphous films at frequencies up to 3⋅10 6 Hz. The density of localized states at the
Fermi level, the mean time for phonon-assisted tunneling, and the hopping distance have
been evaluated for polymorphic TlInS 2 films. For frequencies above 10 7 Hz, σ ac ( f ) ~ f
2 .
Such a behavior is caused by optical transitions in TlInS 2 amorphous films.
Keywords: amorphous film, vapour deposition, Fermi level, dielectric properties,
electrical conductivity.
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