Some physical properties of Ga2Te5 single crystals

Single crystals of Ga2Te5 were prepared by a special modified Bridgman technique. Measurements of the electrical conductivity and Hall effect between 268 and 503 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, from 170 to 511 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 (m*p, m*n), diffusion coefficient (Dp, Dn) and diffusion length (Lp, Ln), as well as the relaxation time (*tp, *tn) and to reveal the general behaviour of this semiconductor.