Faculty Bibliography

Antenna-coupled high-T-c bolometers fabricated from YBa2Cu3O7-delta thin films have been prepared using molecular organic dyes. Light-harvesting layers derived from these visible and near-infrared absorbers have been utilized to produce detectors which exhibit wavelength-selective response characteristics in the visible and near-infrared spectral regions. Using such hybrid structures, initial studies documenting efficient energy transfer between molecular dye layers and superconductor surfaces have been completed. (C) 1996 American Institute of Physics.

Through the use of electrochemical and vacuum deposition techniques, molecular materials are combined with high-T-c superconductors in order to fabricate two new classes of hybrid devices. In the first class of devices, electrochemical methods are utilized to deposit polypyrrole onto YBa2Cu3O7-delta structures. With such systems, experiments are conducted which explore electron transfer events which occur between the conductive polymer and the high-T-c superconductor at temperatures both above and below T-c. Here it is found that the transition temperature (T-c) of the superconductor is depressed dramatically when polypyrrole is oxidized to its conductive form and that it returns to a value which is close to the original value upon reduction of the polypyrrole layer to the neutral, nonconductive form. In the second class of devices, the ability of molecular dye layers to affect the optical properties of YBa2Cu3O7-delta photodetectors is demonstrated. By examining changes in the optical and electronic properties of these systems, energy transfer processes which occur between molecules and high-T-c superconductors are explored. Here it is found that dye layers are able to act as antenna for optical radiation at those wavelengths which the dye layer absorbs light most strongly.