2021   02   en   p.54-60 E.M. Kerimova, S.N. Mustafaeva, N.Z. Gasanov, К.М. Husеynova, Q.M. Sharifov,
TlGa1-xErxSe2 solid solutions, their electrical and optical properties


The complex permittivity, dielectric loss tangent, and conductivity σac of TlGa1-xErxSe2 solid solutions (x = 0; 0.001; 0.005) were studied in the temperature range 150-300 K in an alternating electric field (25-106 Hz). The change in dielectric constant as a function of temperature in the studied crystals is due to the presence of low-frequency relaxation polarization. Conductivity obeys the law σac ~ f 0.8 at frequencies of 102–104 Hz, which, in the studied crystals, indicates the presence of hopping conductivity by states localized near the Fermi level. The parameters of the states localized in the TlGa1-xErxSe2 band gap are estimated. It was shown that an increase in the Er impurity leads to an increase in the density of localized states in TlGaSe2 and a decrease in their energy spread. The optical absorption edge of TlGa1-xErxSe2 crystals was studied, and the temperature dependence of the band gap in them was obtained.

Keywords: solid solutions, complex dielectric permittivity, frequency dispersion, dielectric loss, conductivity, optical absorption edge.
PACS: 72.20.-i ; 78.00.00


Received: 02.06.2021


Institute of Physics, National Academy of Sciences of Azerbaijan, Baku, AZ-1143
E-mail: *ngasanov@yandex.ru

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