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 thermoelectric response to the heat flux propagating through the film, perpendicular to the voltage measurement axis. Good agreement is found between the measured voltage characteristics and a macroscopic model based on the Seebeck tensor of the material. The applicability of such materials to single-photon detectors is discussed. A class of materials with sufficiently large low-temperature Seebeck tensor to construct a high resolution detector has been identified but not yet optimized for this use.