Thermoelectric Sensor of a Single-Photon Detector

We investigated the characteristics of a thermoelectric multilayer sensor of a single-photon detector in the design of which conventional superconductors Pb, Mo, and Nb are used as an absorber and a heat sink. A thermoelectric layer of lanthanum-cerium hexaboride is located between the absorber and the heat sink, and these three layers are located on a dielectric substrate. The results of computer simulation of the heat propagation process in sensors of various geometries with an operating temperature varying from 0.5 to 4.2 K are presented. The temporal dependences of the temperature in different areas of the sensor, the power of the signal arising on it, the equivalent noise power and the signal-to-noise ratio (SNR) during the absorption of single photons with an energy of 0.8, 1.65, and 3.1 eV are determined. The obtained results allow us to state that the proposed design of the sensor with a Nb superconductor can ensure the registration of absorbed single photons with a high efficiency in a wide range of the electromagnetic spectrum.