TEMPERATURE DEPENDENCES OF THE ELECTRICAL-CONDUCTIVITY, HALL-EFFECT AND THERMOELECTRIC-POWER OF TL2SE3 SINGLE-CRYSTALS

The electrical conductivity (sigma) and Hall coefficient (R-H) of sing le crystals grown from a melt have been investigated over the temperat ure range 183-388 K. Our investigation showed that our samples are p-t ype conducting. The dependence of the Hall mobility on temperature was presented graphically. The forbidden energy gap was calculated and fo und to be 1.34 eV whereas the ionization energy of the impurity level was 0.12 eV. The values of the electrical conductivity, Hall coefficie nt and carrier concentration at room temperature were 1.44 x 10(-3) Om ega(-1) cm(-1), 6.33 x 10(5) cm(3) C-1 and 9.39 x 10(11) cm(3) respect ively. The Hall mobility at room temperature (mu(H)) was found to be 9 .886 x 10(2) cm(2) V-1 s(-1). Also, the thermoelectric power (TEP) was investigated in the temperature range 180-376 K. The relation between the TEP and the concentration of charge carriers and electrical condu ctivity was studied. Mobilities, effective masses, relaxation times, d iffusion lengths and diffusion coefficients both for majority and for minority carriers were obtained at room temperature.