Journal of Physical Studies 2(1), 136–138 (1998) DOI: https://doi.org/10.30970/jps.02.136 LOW-FREQUENCY DIELECTRIC SPECTRA OF LOW-RESISTIVITY GaSe CRYSTALS

J. Stakhira, O. Fl'unt, Ya. Fiyala
Ivan Franko Lviv State University, Chair of Semiconductor Physics
50 Drahomanov Str., Lviv UA-290005, Ukraine

The low-frequency dielectric response of low-resistivity GaSe layered crystal along the $c$-axis has been investigated at liquid nitrogen temperatures. The normalized spectra (activation energies from frequency shift is 0.19 eV) have been treated analytically employing equivalent circuits. It is shown that experimental data cannot be obtained with the circuit containing only ideal capacitors and resistors. At the same time, the equivalent circuit containing dispersive capacitors characterized by the power law dependence on frequency $C^*=B(jω)^{n-1}$, where $ω$ is radian frequency, $0< n< 1$, gives a good agreement with experimental data. This means that measured response of low-resistivity GaSe crystals follows the ‟universal" power law of dielectric response $χ^*\sim(jω)^{n-1}$, but not the Debye one. The nature of the ‟universal" power law is explained by many-body interactions between localized charge carriers.

The measurement was carried out by transducing of capacity in voltage in the frequency range of 20 Hz–100 kHz. Samples for study were cloven parallel to the layer with the thickness of $\sim$ 0.8 mm$^2$ from GaSe crystal with resistivity $\sim$ 300 Ohm$\cdot$cm at room temperature. The indium contacts soldered on both fresh cleavages were used as plates of capacitor.

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