Electrical and Thermal Transport Properties of TlGaSe2 Single Crystals

The electrical conductivity (δ) and Hall coefficient (RH) of single crystals prepared by a special modified Bridgman technique have been investigated over the temperature range 245-495 K. Our investigation showed that our samples are p-type conducting. Thedependence of the Hall mobility on temperature was presented graphically. The forbidden energy gap was calculated and found to be2.1 eV whereas the ionization energy of the impurity level was 0.36eV. The values of the electrical conductivity, Hall coefficient andcarrier concentration at room temperature were 1.87 x 10^-6 Ω.1 cm.1,3.98 x10^9 cm3 C.1 and 1.57 x 10^9 cm.3 respectively. The Hall mobilityat room temperature (muH) was found to be 7.46 x 10^3 cm2 V.1s.1. Also,the thermoelectric power (TEP) was investigated in the temperaturerange 271-493 K. The combination of the electrical and thermalmeasurements in the present investigation makes it possible to findvarious physical parameters such as mobilities, effective mass,relaxation times, diffusion coefficients and diffusion lengths both formajority and for minority carriers, Also figure of merit was determined. These parameters reveal the general behavior of this semiconductor.