Thin film pyroelectric arrays as infra-red detectors

Pyroelectric thin film 12-element linear arrays (element size 0.4x0.9 mm(2)) have been fabricated by standard photolithography techniques on silicon substrates. A voltage responsivity of almost 800 V/W in air and 3000 V/W in vacuum is measured at low frequencies (0.1-1 Hz). Measurements are compared to finite element simulations. Doping of lead titanate thin films have been studied. Incorporation of porosity and Ca-doping of lead titanate thin films was found to improve significantly the pyroelectric properties. 20% Ca doping increased p/epsilon to 3.3. Poling experiments with Zr doped lead titanate shows the necessity of high temperature poling to obtain high pyro-coefficients.