Single-Layer Detection Pixel of Single-Photon Thermoelectric Detector Based on Rare-Earth Hexaborides

The results of computer simulation of the heat propagation processes in the single-layer detection pixel of single-photon thermoelectric detector after absorption of photons with the energy of 0.8 eV are presented. The various geometries of detection pixel made from rare-earth hexaborides are considered. As the material of absorber, the lanthanum hexaboride (LaB₆) is chosen, and as the materials of thermoelectric sensor, the hexaborides of cerium (CeB₆), and lanthanum–cerium (La_0.99 Ce_0.01)B₆ are used. The choice of LaB6 as an absorber material had the goal to ensure a high system efficiency of photons detection in the near IR region. The computer modeling was carried out based on the equation of heat propagation from a limited volume, using the three-dimensional matrix method for differential equations. It is shown that the single-photon thermoelectric detector with the single-layer detection pixel made only of hexaborides will have the count rates of GHz and the higher detection efficiency as compared with the sensitive element with the heavy metal as an absorber. In addition, such a sensitive element is more stable mechanically when it is cooled to the operating temperatures of 0.5 and 9 K.