Signal-to-Noise Ratio of the Thermoelectric Single-Photon Detector with CeB6 Sensor and Bi-2223 Absorber

The results of the simulation of heat propagation processes in the multilayer detection pixel of a single-photon thermoelectric detector consisting of heat sink (Bi-2223), thermoelectric sensor (CeB₆), absorber (Bi-2223), and antireflection layer (SiO₂) arranged in series on sapphire substrate (Al₂O₃) are presented. The design of the detection pixel without an antireflection layer is also considered. Simulation of the processes of absorbed photons heat transfer is carried out based on the equation of heat propagation from a limited volume. The cases of absorption of photons with energies of 0.8–1000 eV in detection pixels with a surface of 4 and 1 µm², different thicknesses of absorber and sensor at a fixed operating temperature of the detector of 9 K are studied. Temporal dependences of voltage arising on the sensor, the equivalent power of Johnson and phonon noise are investigated, the signal-to-noise ratio is calculated, and the ways to increase this parameter are proposed.