Thin nickel films as absorbers in pyroelectric sensor arrays

Abstract During the evaporation of nickel on quartz, the square resistance and the IR-transmittance have been investigated simultaneously. A modified Namba model is introduced to explain the measured thickness dependence of resistivity. Inferences on the film growth and the percolation threshold are obtained, which are both important with respect to the absorber quality and fabrication. Thin nickel films of various thicknesses have been deposited on pyroelectric polyvinylidene fluoride (PVDF) films. The transmittance of these two-layer-systems has been measured in the infrared spectral range 2 μm – 50 μm and is compared with theoretical simulations. The absorber characteristic can be varied by an appropriate selection of the thickness of the nickel film. This allows the realization of broadband absorber and of selective absorbers as well. PVDF films coated with optimized nickel absorbers have been used in integrated pyroelectric sensors.