Some physical properties of Ga2Te5 single crystals

Abstract

Single crystals of Ga₂Te₅ were prepared in our laboratory by a special modified Bridgman technique method. Measurements of the electrical conductivity and Hall effect between 268 and $\text{503}\text{K}$ were carried out on Ga₂Te₅ samples in two crystallographic directions (parallel and perpendicular to the c-axis). The Hall coefficient is positive and varies with the crystallographic direction. A unique mobility behaviour and strong anisotropy in the carrier mobility were observed. Also, the present investigation involves the thermoelectric power measurements of Ga₂Te₅ samples in the wide range 170–$\text{511}\text{K}$, when the direction of the temperature gradient is parallel to the layer planes. The combination of the electrical and thermal measurements in the present investigation makes it possible to find various physical parameters such as carrier mobilities, effective masses of free charge carriers $\text{(m}{}_{\mathrm{<mtext>p</mtext>}}{}^{\mathrm{\ast }}\text{,m}{}_{\mathrm{<mtext>n</mtext>}}{}^{\mathrm{\ast }}\text{)}$, diffusion coefficients (D_p,D_n) and diffusion lengths (L_p,L_n), as well as the relaxation time (τ_p,τ_n) and to reveal the general behaviour of this semiconductor.