Flash evaporated layers of (Bi/sub 2/Te/sub 3/-Bi/sub 2/Se/sub 3/)(N) and (Bi/sub 2/Te/sub 3/-Sb/sub 2/Te/sub 3/)(P) used as micro-module-Peltier

Abstract

(Bi/sub 2/Te/sub 3/)/sub 0.9/(Bi/sub 2/Se/sub 3/)/sub 0.1/ for n type material powder and (Bi/sub 2/Te/sub 3/)/sub 0.25/(Sb/sub 2/Te/sub 3/)/sub 0.75/ for p type material powder were evaporated by flash evaporation technique. We obtained a value of Z equal to 0.21/spl times/10/sup -4/ K/sup -1/ for /spl alpha/=40 /spl mu/V/K and /spl rho/=50 /spl mu//spl Omega/.m for p type material and Z about 0.17/spl times/10/sup -3/ K/sup -1/ for a=90 /spl mu/V/K and /spl rho/=30 /spl mu//spl Omega/.m for n type material (at 300K), for 1 /spl mu/m layers thickness deposited over polyimide substrate, before annealing. We show that after annealing at 250/spl deg/C under He atmosphere, the figure of merit of the layers increases to Z=3.2/spl times/10/sup -3/ K/sup -1/ for /spl alpha/=240 /spl mu/V/K and /spl rho/=12 /spl mu//spl Omega/.m for p type material and Z=1.6x10/sup -3/ K/sup -1/ for /spl alpha/=200 /spl mu/V/K and /spl rho/=15 /spl mu//spl Omega/.m for n type material (at 300 K). With these fabrication parameters we realised three different structures of micro-module Peltier (MMP) junctions and we obtained a maximum value for temperature drop between hot and cold sides of about 3.4 K. This result is very promising in order to develop micro-module Peltier (MMP) effects.