Thermoelectric properties of p-type (Bi2Te3)x(Sb2Te3)1-x crystals prepared via zone melting

In the present study, p-type (Bi2Te3),(Sb2Te3)(1-x) crystals with various chemical compositions (x = 0, 0.05, 0.10, 0.16, 0.20, 0.24 and 0.26) were fabricated through the zone melting method. Thermoelectric properties, including Seebeck coefficient (alpha), electrical conductivity (sigma) and thermal conductivity (kappa), were measured in the temperature range of 300-500K. The influence of the variations of Bi2Te3 content (x) on the thermoelectric properties was studied. The increase of Bi2Te3 content (x) caused a decrease in hole concentration and thus a decrease of sigma and an increase of alpha. The maximum figure of merit (ZT = alpha 2(sigma)T/kappa) of 1.14 was obtained at about 350 K for the composition of 24% Bi2Te3-76% Sb2Te3 with 3 wt% excess Te. (c) 2005 Elsevier B.V. All rights reserved.