Photoresistive Response of Superconducting Thin Films
When photons having energies greater than the superconducting energy gap are incident on a superconducting film that is cooled to temperatures near the superconducting transition temperature Tc, there will be a change in the resistivity of the film. This effect can be the basis for an optical detector, such as the superconducting bolometer. High Tc superconductors offer an opportunity for a competitive infrared bolometer which is operated near its relatively high transition edge temperature. Operation in this mode generally precludes a combination of very fast (ns time scale) and very sensitive operation. The bolometric mechanism assumes that the resistance of the film is increased by increasing the temperature of the film, relatively uniformly over the irradiated area. For above gap light this bolometric process will always be present. However, other processes can induce a resistive change which will compete with the bolometric response. The relative importance of the bolometric mechanism relative to other types of processes will depend on the materials parameters and the time scale on which the film is heated and the resistive change is observed.
KeywordsBias Current YBCO Film Granular Film Flux Creep Pair Breaking
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- 8.W. S. Brockelsby et.al., Appl. Phys. Lett. 54, 1175 (1989).Google Scholar
- 16.Q. Y. Ying and H. S. Kwok, submitted to Phys. Rev. (1990).Google Scholar
- 19.M. Sugahara et. al., Phys. Lett. Al25, 429 (1989).Google Scholar
- 24.D. U. Gubser, S. A. Wolf, W. W. Fuller, D. VanVechten, and R. W. Simon, Physica B135, 131 (1985).Google Scholar
- 25.A. M. Kadin, M. Leung, and A. D. Smith, (private communication).Google Scholar
- 27.P. W. Kruse, Semicond. Sci. Technol. 5, 229 (1990).Google Scholar
- 28.M. Leung (private communication).Google Scholar