A METHOD FOR THE MEASUREMENT OF THE THERMAL, DIELECTRIC, AND PYROELECTRIC PROPERTIES OF THIN PYROELECTRIC FILMS AND THEIR APPLICATIONS FOR INTEGRATED HEAT SENSORS

A method is described that enables the simultaneous or consecutive determination of the specific heat, the thermal diffusivity, the dielectric constant, and the pyroelectric coefficient of thin pyroelectric films. The sample is heated by the absorption of intensity modulated light at one surface. The pyroelectric current and the transient temperatures of the sample surfaces are recorded as a function of the modulation frequency of the chopped light. The transient temperature recording is performed via thin-film bolometers. Analysis procedures for the determination of the specific heat, the thermal diffusivity, and the spatially varying pyroelectric coefficient are introduced and discussed. A simulation of the performance of integrated pyroelectric ir sensors on silicon chips is performed by a coupling of the pyroelectric material to a heat sink. It is shown that the response of pyroelectric ir sensors integrated on silicon chips is influenced by heat wave interference effects. Experimental results are given using thin pyroelectric PVDF films. It is shown that the use of pyroelectric polymers for integrated pyroelectric sensors is a good choice, due to their low thermal conductivity.