Experimental studies on primary and secondary pyroelectric effects in Pb(ZrxTi1-x)O3, PbTiO3, and ZnO thin films

The pyroelectric coefficients and pyroelectric response in lead zirconate titanate (Pb(ZrxTi1−x)O3), lead titanate (PbTiO3), and zinc oxide (ZnO) thin films (0.1–2.0-μm thick) have been studied for possible integrated thermosensor applications. Pyroelectric properties of these films deposited on thick (500-μm) silicon substrates and thin (1.0-μm) polysilicon membranes have been investigated. The measured pyroelectric coefficients for these materials are 70, 95, and 1.0 nC/cm2 K for Pb(Zr0.54Ti0.46)O3, PbTiO3, and ZnO, respectively. Coupling effects between the pyroelectric film and substrate were studied. It was observed that the primary pyroelectric effect dominates the pyroelectric response in Pb(Zr0.54Ti0.46)O3 and PbTiO3 thin films while the secondary effect is dominant in ZnO thin films.