Fabrication and characterization of the �?-type (Bi2Te3)�?(Sb2Te3)1�?����? thermoelectric crystals prepared via zone melting

[摘要] In the present study, ð‘�?-type (Bi₂Te₃)_ð‘�?(Sb₂Te₃)_{1â€�?�ð�?��?} crystals with various chemical compositions (ð‘�? = 0.2, 0.22, 0.235, 0.25, 0.265, 0.28 and 0.3) were fabricated through the zone melting method. Thermoelectric properties, including Seebeck coefficient (ð›�?), electrical conductivity (𝜎), thermal conductivity (ðœ�?) and Hall constants, were measured at room temperature, 300 K. The influence of the variations of Bi₂Te₃ content (ð‘�?) on the thermoelectric properties was studied. The increase of Bi₂Te₃ content (ð‘�?) caused a decrease in (carrier) hole concentration and thus a decrease of 𝜎 and an increase of ð›�?. The maximum figure of merit (ð‘�? = ð›�?²ðœŽ/ðœ�?) of 2.7 Ã�? 10^-3 K^-1 was obtained at about 300 K for the composition of 25% Bi₂Te₃â€�??75% Sb₂Te₃ with 3wt% excess of Te.

[学科分类] 材料工程

[关键词] Zone melting method;Biâ€�?�Sbâ€�?�Te anisotropy;ambipolar component;antistructure defect.