Thermoelectric Effect of YBa₂Cu₃O_7-δ Films with Risetime of 0.6 Nanosecond

Voltage pulses of 90 V have been observed in YBa₂Cu₃O_7-δ films with a tilted orientation when they are illuminated by pulsed laser at room temperature. The signals result from the anisotropy of thermoelectricity in the films. The thermoelectric signals related to the tilted angle are linear to the laser power and wavelength-independent. It is shown that the response of films to the mode-locked laser has a risetime less than 1ns and width less than 20 ns. The films with the superconducting transition temperature of 90K were prepared by laser ablation.