Flash evaporated layers of (Bi2Te3-Bi2Se3)(N) and (Bi2Te3-Sb2Te3)(P)

(Bi2Te3)(0.9)(Bi2Se3)(0.1) for N-type material powder and (Bi2Te3)(0.25)(Sb2Te3)(0.75) for P-type material powder were evaporated by a flash evaporation technique. We obtained a value of Z equal to 0.21 X 10(-4) K-1 for alpha = 40 mu VK-1 and rho = 50 mu Ohm . m for P-type material and Z of about 0.17 X 10(-3) K-1 for alpha = 90 mu VK-1 and rho = 30 mu Ohm . m for N-type material (at 300 K), for 1 mu m layer thickness deposited over polyimide substrate, before annealing. We show that after annealing at 250 degrees C under He atmosphere, the figure of merit of the layers increases to Z = 3.2 X 10(-3) K-1 for alpha = 240 mu VK-1 and rho = 12 mu Ohm . m for P-type material and Z = 1.6 X 10(-3)K(-1) for alpha = 200 mu VK-1 and rho = 15 mu Ohm . m for N-type material (at 300 K). With these fabrication parameters, we realised three different structures of micromodule Peltier (MMP) junction and we obtained a maximum value for temperature drop between hot and cold sides of approximate to 3.4 K. This result is very promising in order to develop MMP. (C) 1998 Elsevier Science S.A. All rights reserved.