Optical effects in superconducting heterostructures

A new method for synthesis of high Tc superconducting films and wires via electrochemical route has been developed by the author and considerable amount of work has been carried out during last eight years. The present paper summarizes the synthesis of superconductor/metal/semiconductor heterostructure via electrochemical route. The quaternary alloyed films of Bi-Sr-Ca-CuO are deposited onto silver substrate using electrodeposition technique. These films are electrochemically oxidized in 1N KOH solution. On these superconducting films, CdSe semiconducting films are deposited using the same technique. Thus, Ag/Bi-Sr-Ca-CuO/CdSe or CdSe/Ag/Bi-Sr-Ca-CuO heterostructures are fabricated. Photoinduced characteristics of these heterostructures are studied by illuminating either CdSe or Bi-Sr-Ca-CuO at different intensities at room and at low temperatures I-V characteristics in dark and under illumination are measured at low as well as at room temperatures. The contact potential is also sensitive to light and is a function of temperature. Optical detection of Tc has also been carried out. The details about the properties of heterostructure will be presented. (author)