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 single photons with 0.8 eV energy are presented. Various geometries of detection pixel made from rare-earth hexaborides are considered. Lanthanum hexaboride (LaB₆) as the absorber material, cerium (CeB₆), and lanthanum–cerium (La₀.99Ce₀.01)B₆ hexaborides were chosen as materials of thermoelectric sensor. Selection of LaB₆ as absorber material was aimed to provide high system efficiency of photons detection in the near IR region. Computer modeling based on the equation of heat propagation from the limited volume, using the three-dimensional matrix method for differential equations, was carried out. It is shown that a single-photon thermoelectric detector with a single-layer sensitive element made only of hexaborides will have gigahertz count rate and higher detection efficiency than the sensitive element with the heavy metal absorber. In addition, such sensitive element is mechanically more stable when it is cooled to operating temperatures of 0.5 and 9 K