Black aluminum-coated Pt/Pb(Zr0.56Ti0.44)O3/Pt thin film structures for pyroelectric energy harvesting from a light source

Abstract

A black aluminum (B-Al) film was deposited onto the surface of a stack structure of platinum/Pb(ZrxTi1 − x)O3/platinum (Pt/PZT/Pt) to convert light into a heat variation and the heat variation into a polarization change. A comparison was performed between B-Al/Pt/PZT/Pt and conventional Pt/PZT/Pt structures. An absorbance higher than 95% was measured for the B-Al layer over a large range of wavelengths varying from 350 nm to 1000 nm. The theoretical model shows that heat diffusion was extremely fast through the layers, and the sample holder played a key role in the variation and stabilization of the system temperature. A doubled variation of the polarization was observed when the light was applied onto the surface of the stack structure with stable B-Al on the top. This behavior was interpreted by the larger temperature variations induced under the highly absorptive B-Al layers, in good correlation with the theoretical model prediction based on the heat fluxes in the structures. This result is very promising for possible pyroelectric energy harvesting applications.