Application of a conductive polymer to self-absorbing ferroelectric polymer pyroelectric sensors

This paper presents application of a conductive polymer to a self-absorbing pyroelectric sensor. The pyroelectric sensor is a free standing thermal infrared detector. It consists of a conductive polymer (PEDT/PSS) as an absorber layer and front electrode, a PVDF film as the pyroelectric material and a Ni-Al metal film as a reflector layer and rear electrode. Theoretical analysis of the infra red absorptivity of this structure shows that a selective, self-absorbing pyroelectric sensor with an absorptance of up to 90% is feasible. The conductive polymer, PEDT/PSS with added organic binders, is coated on PVDF film using both spin-coating and solution-casting techniques. The deposition technology of the conductive polymer is shown to be a non-critical process with a high reproducibility and compatible with PVDF film. The measured response of this PVDF pyroelectric sensor is shown to be 10 times higher than that of a commercially available PVDF film with thin nickel aluminium front and back electrodes. (C) 1999 Elsevier Science B.V. All rights reserved.