Doping of Bi2Te3 based alloys for thermoelectric cooling applications

TE.Coolers are now finding widespread uses in microelectronic and optoelectronic fields since the performance of various devices is critically dependent upon temperature. This paper discusses our recent results on the synthesis, growth and characterization of these alloys. Alloys with composition Bi0.5Sb1.5Te3+x (x=0-0.3) and Bi2Se0.3Te2.7+x (x=0-0.3) for p and n conductivity respectively were synthesized and grown using different cooling rates. The dependence of the microstructure of the solidified ingot on tellurium excess was studied. The thermoelectric figure of merit Z for p type materials could be optimized at similar to 2x10(-3)/K for the composition Bi0.5Sb1.5Te3.2 In n type material, Z = 2x10(-3)/K was obtained with SbI3 doping.