Hideki Morimitsu

Fabrication of Bi2-xSbxTe3 (x=0-1.5) Thick Film by Centrifugal Deposition

A Bi2-xSbxTe3(x=0-1.5) thick film thermoelectric element was fabricated using centrifugal deposition and its Sb content-dependent thermoelectric properties were investigated. When the Sb content was low (x=0.5), two types of fine structure along the direction of the thickness were observed. Pole figure measurements revealed that the vicinity of the film surface was composed of single crystal layers oriented along the c-axis and the vicinity of the interface with the substrate was composed of randomly orientated layers. As the content of Sb increased, the degree of orientation improved, and at x=1.5 the entire film was close to a single crystal. A Bi0.5Sb1.5Te3 thick film showed p-type thermoelectric properties and a thermoelectric power factor of 3.5 ×10-3W/mK2. It was thus demonstrated that centrifugal deposition can be used to fabricate thermoelectric elements with high efficiency.