Low-Temperature Processing of High-Performance 0.74Pb(Mg1/3Nb2/3)O3-0.26PbTiO3 Thin Films on La0.6Sr0.4CoO3-Buffered Si Substrates for Pyroelectric Arrays Applications

Abstract

To prepare high-performance ferroelectric thin films on Si substrates for pyroelectric arrays applications, 0.74Pb(Mg1/3Nb2/3)O3–0.26PbTiO3 (PMN–PT) thin films, with composition beyond morphotropic phase boundary, were deposited by radio-frequency magnetron sputtering. Conductive perovskite La0.6Sr0.4CoO3 with resistivity of about 20 μΩ cm was used as a buffer layer between PMN–PT and Pt/Ti/SiO2/Si substrates to promote perovskite phase formation for the PMN–PT thin films. The PMN–PT thin films with pure perovskite phase have been obtained at temperatures as low as 500°C, which is compatible with integrated circuits. The ferroelectric, dielectric, and pyroelectric properties of the films were investigated. It is found that the films exhibit a large remnant polarization of 29.2 μC/cm2 and a high pyroelectric coefficient of 9.4 × 10−4 C/m2 K at room temperature. The calculated figures of merit for current responsivity, voltage responsivity, and detectivity are 3.76 × 10−10 m/V, 0.02 m2/C, and 1.29 × 10−5 Pa−1/2, respectively. These features suggest the film a promising material for thermal imaging applications based on silicon technology.