Electrical and thermoelectric properties of SbI3-doped 33.3%Bi2Te3-66.7%Sb2Te3 thermoelectric semiconductors

摘要

The temperature dependences of the electrical andthermoelectric properties of the SbI3-doped 33.3% Bi2Te3-66.7%Sb2Te3 single crystals have been measured at temperatures rangingfrom 77K to 600K. The scattering parameter of the 33.3%Bi2Te3-66.7% Sb2Te3 single crystals was determined as s=0.With increasing the amount of SbI3 dopant, the hole concentrationof the 33.3% Bi2Te3-66.7% Sb2Te3 single crystal is decreased,resulting in the increment of the Seebeck coefficient and electricalresistivity, and the temperature for the maximum figure-of-meritshifted to lower temperature. A maximum figure-of-merit of2.3×10-3/K was obtained for 0.3 wt% Sbi3-doped specimen. Ithas been revealed that the addition of SbI3 as a donor dopant isuseful in controlling the hole concentration of p-type 33.3%Bi2Te3-66.7% Sb2Te3 alloy system.