Substrate effect on the evolution of the current-voltage response of a pyroelectric sensor

Pyroelectric sensors are designed as multi-layer structure consisting essentially of an absorbent layer, a pyroelectric film and a radiator substrate; we modify this structure by varying the thickness of the absorbent layer, measured by ellipsometer technique, and the nature of the substrate. Initially the pyroelectric signal is measured using a look-in amplifier type SR 830, and thereafter the sensor is placed in a conventional circuit; then we study the evolution of the current -voltage response, collected on an oscilloscope and saved in a excel file, with the nature of the substrate and for a given thickness of the absorbent layer. The results are discussed in terms of the evolution of charging time, the discharging time and the amplitude of the pyroelectric sensor response as function of the thermal conductivity of the substrate.