Measurements of transport properties of TlGaSe2 crystals

TlGaSe2 single crystals were grown by modified Bridgman method. The crystals were identified structurally by X-ray diffraction. Measurements of electrical conductivity and Hall effect were performed in the range (200–492 K) and (163–602 K) for thermoelectric power (TEP) measurements. Anisotropic nature of the layered TlGaSe2 crystal was investigated. Hall effect and thermoelectric power measurements revealed the extrinsic p-type conduction in the low temperature range of the study. The analysis of the temperature-dependent electrical conductivity and carrier concentration reveal that the acceptor level is located at 0.2 eV above the valence band of TlGaSe2. From the obtained experimental data, the main characteristic parameters of the crystals have been estimated. Energy gap and acceptor concentration were 2.23 eV and 9.6 × 1013 cm−3 respectively.