Utilizing the Transverse Thermoelectric Effect of Thin Films for Pulse Laser Detection

In this work, pulse laser detectors based on the transverse thermoelectric effect of YBa₂Cu₃O_7-δ thin films on vicinal cut LaAlO₃ (001) substrates have been fabricated. The anisotropic Seebeck coefficients between ab-plane (S) and c-axis (S) of thin films are utilized to generate the output voltage signal in such kind of detectors. Fast response has been determined in these sensors, including both the rise time and the decay time. Under the irradiation of pulse laser with the pulse duration of 5-7 ns, the output voltage of these detectors shows the rise time and the decay time of 6 and 42 ns, respectively, which are much smaller than those from other materials. The small rise time in YBa₂Cu₃O_7-δ-based detectors may be due to its low resistivity. While the high thermal conductivity and the large contribution of electronic thermal conductivity to the thermal conductivity of YBa₂Cu₃O_7-δ are thought to be responsible for the small decay time. In addition, these detectors show good response under the irradiation of pulse lasers with a repetition rate of 4 kHz, including the precise determinations of amplitude and time. These results may pave a simple and convenient approach to manufacture the pulse laser detectors with a fast response.