Imaging detectors based on anisotropic thermoelectricity

Transient voltage pulses spontaneously occur in anisotropic films following the absorption of photons. Experiments on normal state YBCO unambiguously confirm that the pulses sensed between the sample ends arise from the therm oelectric response to the heat flux propagating through the film, perpendic ular to the voltage measurement axis. Good agreement is found between the m easured voltage characteristics and a macroscopic model based on the Set be ck tensor of the material. The applicability of such materials to single-ph oton detectors is discussed. A class of materials with sufficiently large l ow-temperature Seebeck tensor to construct a high resolution detector has b een identified but not yet optimized for this use. (C) 2000 Published by El sevier Science B.V. All rights reserved.