Fabrication and Optical Properties of Ferroelectric Photonic Crystals by Electrophoretic Epitaxial

本文研究了利用溶胶-凝胶法结合电子束光刻技术制备抗蚀剂模具的铁电光子晶体及其光学性质。具体而言，对以下一组实验进行了调查，得到的主要结果如下：1。溶胶-凝胶法制备二维（Pb, La）（Zr, Ti）O_3 [PLZT]光子晶体及其光学性质：利用电子束（EB）光刻技术将市购PLZT前驱体溶液浇铸到Nb-STO基板上形成的抗蚀剂模中，成功地在掺nb的SrTiO_3 [Nb-STO]单晶基底上制备了由PLZT陶瓷柱组成的六角形光子晶体，该晶体具有导电性和电极作用。然后在725℃的空气中烧制。得到的2D-PLZT光子晶体具有属于光子带g的特征光学反射光谱。此外，通过使用扫描探针显微镜（SPM）测量压电响应特性，发现单个PLZT柱具有铁电性。电泳沉积（EPD）制备BaTiO_3 [BTO]光子晶体：在Pt/SiO_2/Si衬底上成功制备了由BTO陶瓷柱组成的六角形光子晶体，并用eb光刻技术在衬底上形成抗蚀模，并用高浓度醇盐溶胶-凝胶法制备了10-15 nm的BTO纳米晶体。将纳米晶BTO柱在空气中进行600 ~ 700℃热处理烧结。获得的单个BTO柱具有明确的铁电性，并通过SPM.3的压电响应特性测量得到了证实。BTO纳米晶外延组装成具有晶体单晶性质的聚集体的观察：利用纳米晶EPD制备具有晶体单晶性质的BTO微图是本研究的主要目的。为了使其成为可能，必须建立一种能够实现具有相同晶体坐标的自组装纳米粒子聚集形成的技术。我们首次成功地找到了在水热条件下产生的聚集体中BTO纳米晶体外延组装的明确证据，并通过对其暗场和高分辨率透射电子显微镜（TEM）图像和电子衍射图像的分析得到了证实。少

This research concerns the fabrication and optical properties of ferroelectric photonic crystals by a sol-gel method combined with electron-beam lithography used for preparation of resist molds. Specifically, an investigation on a set of the following experiments has been made and the main results obtained are described below.1. Fabrication of two-dimensional (Pb, La)(Zr, Ti)O_3 [PLZT] photonic crystals using a sol-gel method and their optical properties :2D-photonic crystals consisting of PLZT ceramic pillars arrayed in a hexagonal lattice have been successfully fabricated on Nb-doped SrTiO_3 [Nb-STO] single crystal substrates, which are conductive and act as electrode, by casting a commercially obtained PLZT precursor solution into resist molds formed on the Nb-STO substrates using electron beam (EB) lithography, followed by firing at 725℃ in air. The obtained 2D-PLZT photonic crystals were confirmed to exhibit characteristic optical reflection spectra attributable to photonic band g … More aps (PBGs) formed in the photonic crystals. And moreover, the individual PLZT pillars have been revealed to be ferroelectric, confirmed by measurements of piezoelectric response characteristics using scanning probe microscopy (SPM).2. Fabrication of BaTiO_3 [BTO] photonic crystals by electrophoretic deposition (EPD) of BTO nanocrystals:2D-photonic crystals consisting of BTO ceramic pillars arrayed in a hexagonal lattice have been successfully fabricated on Pt/SiO_2/Si substrates, on which resist molds were formed by EB-lithography, by an EPD method using suspension of 10-15 nm BTO nanocrystals synthesized by high concentration alkoxides sol-gel method. Nanocrystalline BTO pillars were heat-treated at 600-700℃ in air to sinter them. The obtained individual BTO pillars exhibited definite ferroelectricity, confirmed by measurements of piezoelectric response characteristics by SPM.3. Observation of epitaxial assembly of BTO nanocrystals into aggregates with crystallographic single crystal nature :Fabrication of BTO micropatterns with crystallographic single crystal nature by nanocrystals EPD is the main objective of this research. To make it possible the establishment of a technique that can realize formation of nanoparticles aggregation self-assembled to have the same crystallographic coordinates is a must. We succeeded for the first time in finding definite evidence for epitaxial assembly of BTO nanocrystals in aggregates produced under hydrothermal conditions, confirmed by analyses of their dark-field and high resolution transmission electron microscopy (TEM) images and electron diffraction images. Less