Effect of pressure on electrical conductivity of TlInse2 single crystals

Abstract

The effect of hydrostatic pressure on the electrical conductivity of a TlInSe2 single crystal along the tetragonal axis [001] is studied in the range from 0 to 14 × 106 kPa. It is revealed that in this case the dependence of electrical conductivity on pressure follows the law: σ(P) =σ(0) e−GP/2kT which holds true for cases of linear narrowing of the band gap with pressure. It is found that the pressure coefficient of the band gap G = ∂Eg(P)/∂P responsible for the change in the electrical conductivity with pressure amounts to G = (∂ In σ(P)/∂P) 2kT = −1.75 × 10−10eV/Pa which coincides in the order of magnitude with the coefficient G[001] = −(3 to 4) × 10−10 eV/Pa characterizing the narrowing (widening) of the indirect energy gap for a uniaxial compression (expansion) of the given crystals along [001].

Effect of High Pressure on the Electrical Conductivity of TlInX2 (X = Se, Te) Layered Semiconductors

“…Earlier reports on optical absorption edge measurements on TlInSe, under truly hydrostatic pressures showed dEi/dP = 1.48 x lo-'' eV/Pa [6, 141. Resistivity and Hall effect measurements under hydrostatic pressure give dE,/dP = -(2.5 to 3.5) x 10l o eV/Pa [2] and (-1.7 x lo-" eV/Pa) [7], respectively. Our results are slightly higher than those reported in [2], possibly because of the quasi-hydrostatic nature of the pressure.…”

“…Observation of the effect of a truly hydrostatic pressure on the absorption edge [6], the electrical resistivity [7], and the Raman spectra [2] of TlInSe, have been reported earlier, but the pressure was limited only to 1 GPa. The present paper reports the results of an investigation of the dc electrical conductivity of TlInX, (X = Se, Te) compounds under high quasi-hydrostatic pressures, up to 7.0 GPa, and temperatures down to liquid nitrogen.…”

Impacts of Temperature and Frequency on the Dielectric Properties for Insight into the Nature of the Charge Transports in the Tl2S Layered Single Crystals

“…This advantage has not been applied in large scale to chalcogenide semiconductors containing thallium [8]. The interest of these materials is stimulated not only by their fundamental properties but also by possible practical applications [9][10][11][12][13][14]. Layered crystals of chalcogenide semiconductors usually contain structural defects, such as dislocations and vacancies.…”