Self-biased dielectric bolometer from epitaxially grown Pb(Zr,Ti)O3 and lanthanum-doped Pb(Zr,Ti)O3 multilayered thin films

A self-biased dielectric bolometer has been realized by epitaxially grown lead zirconate titanate Pb1.1(Zr0.3Ti0.7)O3 (PZT 30/70) and lanthanum-doped lead zirconate titanate Pb0.83La0.17(Zr0.3Ti0.7)0.9575O3 (PLZT 17/30/70) multilayered thin films using the sol-gel technique. The high-resolution transmission electron microscopy images and electron diffraction pattern showed that the multilayered film had its preferred (111) orientation and the epitaxial growth between the PZT 30/70 and PLZT 17/30/70 layers. The self-biased phenomenon and a large pyroelectric current were observed in the prepoled sample without any external bias at the PLZT 17/30/70 phase transition temperature of 120 °C. Pyroelectric coefficient as high as 990 μC/m2K is obtained in the multilayer thin films around 120 °C. It is obvious that there exists an induced polarization in the PLZT 17/30/70 layer. We attribute this self-biased effect to the strong remnant polarization in the immediately contacted tetragonal PZT 30/70 layers.

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