A Thin-Film Pyroelectric Detector

A dual element, point, infra-red detector is being developed from a sol-gel deposited PbTiO3 thin-film on a micro-machined silicon substrate. Patterning of the ferroelectric film and the electrodes is accomplished by photolithographic techniques. Membranes to reduce the thermal conduction from the sensor elements are created in the underlying substrate by anisotropic etching of the silicon. The measured voltage responsivity (R(V)) as a function of radiation modulation frequency is compared to theoretical predictions and to conventional pyroelectric detector characteristics. Optimisation of the performance with respect to the device design is discussed.