On Microscale Heat Transfer in Thin Film Pyroelectric Sensors

Results are presented from numerical simulations of transient temperature distributions in one-dimensional (ID) and two-dimensional (2D) layered materials with relevance to pyroelectric thin film sensor devices. Simulations are conducted for both Fourier\u27s heat conduction law and for the Equation of Phonon Radiative Transfer (EPRT) to investigate the significance of microscale heat transfer effects. An efficient parallelization scheme is described which makes the numerical solution to the 2D EPRT feasible by direct finite difference solution. Material properties are chosen to ensure compatibility with bulk thermal conductivity and heat capacity measurements. Effects of material thickness, designation of the material properties, and predicted external thermal conductivity and boundary resistance are discussed for layered SiO2 and Diamond films. It is shown that substantial deviations from Fourier\u27s law occur for relevant film dimensions. Implications for sensor design and modeling are discussed