Self-biased dielectric bolometer from epitaxially grown Pb(Zr,Ti)O_(3) and lanthanum-doped Pb(Zr,Ti)O_(3) multilayered thin films

摘要

A self-biased dielectric bolometer has been realized by epitaxially grown lead zirconate titanate Pb_(1.1)(Zr_(0.3)Ti_(0.7))O_(3) (PZT 30/70) and lanthanum-doped lead zirconate titanate Pb_(0.83)La_(0.17)(Zr_(0.3)Ti_(0.7))_(0.9575)O_(3) (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℃. Pyroelectric coefficient as high as 990 μC/m~(2)K is obtained in the multilayer thin films around 120℃. 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.