PbTiO3 thin films for pyroelectric detection

Due to its high pyroelectric coefficient, low permittivity and relatively low piezoelectric coefficients, lead titanate is an important candidate for use in pyroelectric detectors. Sol-gel processing of lead titanate thin films, in combination with micro-machining of silicon substrates, is being used for the development of low-cost infra-red detectors with properties equivalent to existing “bulk” or single crystal devices. Here we report on some aspects of the sol-gel chemistry, the optimisation of the pyroelectric figure of merit and the fabrication and characterisation of an infra-red detector, consisting of two pyroelectric elements on a micro-machined SiO₂-Si₃ N₄ membrane