Effects of the substrate on the response of pyroelectric detectors

In our studies dealing with a theoretical analysis on the response of pyroelectric detectors, it has been found that for substrate-attached pyroelectric detectors, the current responsivity falls off with decreasing frequency below a certain frequency due to the flow of heat out of the pyroelectric crystal into the substrate. The rate of the falloff depends on the thermal conductivity of the substrate. The higher the thermal conductivity, the faster the rate of the falloff. The current responsivity flattens out in a lower intermediate frequency range of 10
^-2
to 10
²
Hz. In this flat plateau region, the smaller the substrate thermal capacity, the higher the current responsivity. The theoretical analysis agrees with the experimental results using LiTaO
3
detectors mounted on silicon substrates.