Pyroelectric figure of merit in alternating hemicyanine/NC Langmuir-Blodgett films incorporating barium ions

Pyroelectric properties in alternating hemicyanine (DAEP)/nitrogencrown (NC) Langmuir-Blodgett (LB) films and effects of incorporating barium cations on pyroelectric behaviors have been investigated. Its pyroelectric coefficient measured is found to be 58 mu C m(-2) K-1 at 300 K. Their dielectric properties have been measured and used to determine the figures of merit in thermal devices. Relative permittivity (epsilon(r)) and dielectric loss values (tan delta) of pyroelectric films (in the range of 1-100 KHz) are found to be 2.34-1.96 and 0.08-0.04, respectively. These data give a maximum pyroelectric figure of merit of 150 mu C m(-2) K-1 in the alternating LB films incorporating barium ions. The effects of different deposition on pyroelectric properties are also discussed in this paper. (c) 2005 Elsevier B.V. All rights reserved.