Prospects for Peltier cooling of the cuprate superconductors

The figure of merit z of commercial Peltier modules has been measured to drop from z=2.3×10^-3 K^-1 with the warm end near 295 K to z=4×10^-4 K^-1 with the warm end at 80 K. Therefore, for reaching the superconducting temperature range even for the cuprates with the highest critical temperature T_c≈130 K, new thermoelectric materials with their maximum value of z around 150 K or lower must be developed. We present experimental results on p- and n-doped compounds of the family Bi_2-xSb_xTe_3-ySe_y showing improved values of z at 150 K and below. We have studied in particular the influence of sintering