A FERROELECTRIC-SUPERCONDUCTING PHOTODETECTOR

A ferroelectric-superconducting photodetector has been developed and c haracterized, An atomically ordered PbZrTiO3 (PZT) ferroelectric gate was grown over a c-oriented YBa2Cu3O7-x (YBCO) high T-c, superconducto r substrate by excimer laser deposition. Irradiation of the PZT gate w ith photons near the ferroelectric gap energy resulted in a measurable change of the drain-source photocurrent with the device at a temperat ure near T-c of the YBCO. The critical temperature of the YBCO base wa s shifted up to 3 K when the PZT gate was irradiated with photon flux of wavelength from 300 to 500 nm. A responsivity of 360 A/W was measur ed and an upper bound on response time to optical irradiation of 100 n s was determined. (C) 1996 American Institute of Physics.