HTSC films for novel optronic devices

ABSTRACT The discovery of high Tc superconductors has revealed promising applications in optoelectronics. However a basic requirement for the development of successful novel optronic devices is the ability to fabricate high quality Josephson, tunnel or three terminal devices in a reproducible, controllable and reliable way.Large area deposition of YBCO multilayers, whole wafer processing techniques are essential and in great progress. Nevertheless, the degradation of the YBa2Cu3O7-x surface layer close to the junction contacts is observed and induces severe limitations in the devices performances. Experimental evidence of such problems and possible solutions will be presented. 1. INTEREST OF HTC JUNCTIONS FOR PHOTON DETECTION Optoelectronic applications using high-Tc superconducting oxides have recentlyattracted much attention [ 1-5J . For instance the feasibility of sensitive high-bandwidth infrared detectors with a wide optical band should provide important applications in the field of space, communications and military industries.In the past highly sensitive detectors have been made in Grain-Boundary Josephsonjunctions (GBJ) formed in BaPbl-xBixO3 (BPBO) 16] and more recently in Bal-xKxBiO3