Effect of composition on the electrical properties and thermal conductivity of Pb1-xSnxTe

P-type Pb1 - xSnxTe single crystals were prepared by a Bridgman method with various Sn content (x). Electrical conductivity (sigma) , Hall coefficient (R-H) and thermal onductivity (kappa) were measured in the temperature range of 300 to 700 K. Hole concentration at 77 K changed from 2.0 x 10(24) to 4.9 x 10(26)m(-3) as x varied from 0 to 1.0. The sigma value increased monotonously with increasing x. The minimum of K found at x = 0.25 were resulted from that of the lattice thermal conductivity (kappa(lattice)) , since the phonon-phonon scattering in the solid solution may have decreased the lattice thermal conductivity. The ratio of electrical conductivity to thermal conductivity (sigma/kappa), to which the figure of merit Z is proportional, increased with increasing N and then reached its maximum at x = 0.5. It was revealed that the thermoelectric performance of Pb1 - xSnxTe can be improved by controlling its composition.