Defect induced structural and thermoelectric properties of Sb_2Te_3 alloy

摘要

Structural and thermoelectric properties of metallic and semiconducting Sb_2Te_3 are reported. X-Ray diffraction and Raman spectroscopy studies reveal that semiconducting sample has higher defect density. Nature and origin of possible defects are highlighted. Semiconducting Sb_2Te_3 hosts larger numbers of defects, which act as scattering center and give rise to the increased value of resistivity, thermopower, and power factor. Thermopower data indicate p-type nature of the synthesized samples. It is evidenced that the surface states are often mixed with the bulk state, giving rise to metallicity in Sb_2Te_3. Role of different scattering mechanism on the thermoelectric property of Sb_2Te_3 is discussed.