Optical and thermal response of thick YBCO-Bismuth junctions

Abstract

Thick (50 micron) films of YBCO (Yttrium Barium Copper Oxide) and Bismuth were prepared as a two-stage thermopile and single stage junctions on Zirconia substrates. The critical temperature of the YBCO films was found to be 85 K. The thermal and optical response of the junctions were studied using a He-Ne Laser of 10 mW power. In the two-stage thermopile (T-sT) configuration, in thermal response, a signal of 20 /spl mu/V was observed for the junction near the critical temperature, corresponding to a temperature difference of a fraction of a degree. In the single stage geometry (S-sG) no significant thermal voltages were found near Tc but photothermionic transitions were observed.