Tang Haixiong, Zhou Zhi, Bowland Christopher C, Sodano Henry A
Nanotechnology. 2015 Aug 28;26(34):345602. doi: 10.1088/0957-4484/26/34/345602.
Perovskite structure (ABO(3)) thin films have wide applications in electronic devices due to their unique properties, including high dielectric permittivity, ferroelectricity and piezoelectric coupling. Here, we report an approach to grow highly textured thick lead titanate (PbTiO(3)) filmson conductive substrates by a two-step hydrothermal reaction. Initially, vertically aligned TiO(2) nanowire arrays are grown on fluorine-doped tin oxide (FTO) coated glass, which act as template crystals for conversion to the perovskite structure. The PbTiO(3) films are then converted from TiO(2) NW arrays by diffusing Pb(2+) ions into the template through a second hydrothermal reaction. The dielectric permittivity and piezoelectric coupling coefficient (d(33)) of the PbTiO(3) films are as high as 795 at 1 kHz and 52 pm V−1, respectively. The reported process can also potentially be expanded for the assembly of other complex perovskite ATiO(3) (A = Ba, Ca, Cd,etc) films by using the highly aligned TiO(2) NW arrays as templates. Therefore, the approach introduced here opens up a new door to synthesize ferroelectric thin films on conductivesubstrates for application in sensors, actuators, and ultrasonic transducers that are important in various industrial and scientific areas.
钙钛矿结构（ABO₃）薄膜因其独特性能，包括高介电常数、铁电性和压电耦合，在电子器件中具有广泛应用。在此，我们报道一种通过两步水热反应在导电衬底上生长高度织构化厚钛酸铅（PbTiO₃）薄膜的方法。首先，在氟掺杂氧化锡（FTO）涂覆的玻璃上生长垂直排列的TiO₂纳米线阵列，其作为模板晶体用于转化为钙钛矿结构。然后通过第二次水热反应将Pb²⁺离子扩散到模板中，使PbTiO₃薄膜从TiO₂纳米线阵列转化而来。PbTiO₃薄膜在1 kHz时的介电常数高达795，压电耦合系数（d₃₃）为52 pm V⁻¹。所报道的工艺还可能通过使用高度排列的TiO₂纳米线阵列作为模板，扩展用于组装其他复杂钙钛矿ATiO₃（A = Ba、Ca、Cd等）薄膜。因此，这里介绍的方法为在导电衬底上合成铁电薄膜开辟了一扇新门，可应用于在各种工业和科学领域都很重要的传感器、致动器和超声换能器。
