THERMOELECTRIC EFFECT IN NORMAL-STATE YBA2CU3O7-DELTA FILMS

Signal pulses of several 100 volts and currents of several amperes have been obtained at lateral surface contacts on normal-state YBa2Cu3O7-delta films in response to pulsed laser irradiation. The signals are shown to be of thermoelectric origin. Thermoelectric fields transverse to the laser-induced temperature gradient are due to the anisotropy of the thermopower in YBa2Cu3O7-delta giving rise to non-zero off-diagonal elements S(ij) is-proportional-to alpha of the Seebeck tensor for films prepared with a tilt angle alpha between the film c-axis and the film surface normal. Large-tilt-angle films (up to alpha = 20-degrees) could be grown on specially cut substrates and may be useful as almost wavelength-independent room temperature radiation detectors.