High quality colloidal crystals with different architectures and their optical properties [Elektronische Ressource] / vorgelegt von Jianhui Ye

Jianhui Ye

Informations

• Publié par: johannes_gutenberg-universitat_mainz
• Publié le: 01 janvier 2007
• Nombre de lectures: 9
• Langue: English
• Poids de l'ouvrage: 39 Mo

Extrait

High Quality Colloidal Crystals
with Different Architectures
and their Optical Properties


Dissertation zur Erlangung des Grades
„Doktor der Naturwissenschaften“
am Fachbereich Chemie, Pharmazie und Geowissenschaften
der Johannes Gutenberg-Universität in Mainz


vorgelegt von


Jianhui Ye


geboren
in Jiangsu, V. R. China


Mainz 2006























Contents I
Contents

1. Introduction ......................................................................................... 1
1.1 Background ...................................................................................................................... 2
1.2 1D, 2D, and 3D Photonic Crystals and their Applications............................................... 5
1.2.1 1D Photonic Crystals................................................................................................. 6
1.2.2 2D Photonic Crystals 6
1.2.3 3D Photonic Crystals 7
1.2.4 Functional Photonic Crystals .................................................................................. 13
1.3 Fabrication of Photonic Crystals from Colloidal Spheres.............................................. 17
1.3.1 Synthesis of Monodisperse Colloidal Spheres........................................................ 17
1.3.2 Crystallization of Monodisperse Spheres................................................................ 21
1.3.3 Photonic Properties of Colloidal Crystals .............................................................. 23
1.4 Motive and Goals of this Work ...................................................................................... 25

2. Fabrication of 3D Photonic Crystals from Colloidal Spheres......................27
2.1 Preparation of Monodisperse PMMA Spheres by SFEP ............................................... 27
2.2 Characterizing of PMMA Spheres ................................................................................. 29
2.2.1 Determination of the Sphere Sizes and Size Distributions ..................................... 30
2.2.2 Surface Charge Analysis ......................................................................................... 35
2.3 Fabrication and Characterization of PMMA Opals........................................................ 36
2.3.1 Crystallization on Horizontal Substrates................................................................. 37
2.3.2 Crystallization on Vertical Substrates..................................................................... 41
2.3.3 PMMA Opal Structure Analysis by SEM............................................................... 44
2.3.4 Optical Properties of PMMA Opaline Films........................................................... 48
2.3.4.1 Angular Dependent Transmission Spectra....................................................... 49
2.3.4.2 Angular Dependent Reflectance Spectra.......................................................... 54
2.3.4.3 High Order Diffraction Bands of PMMA Opals.............................................. 56
2.3.5 Spatially Resolved Microscopy............................................................................... 60



Contents II
2.4 Fabrication of Silica Opals from Large SiO Spheres.................................................... 62 2
2.4.1 Cleaning and Characterizing of Large SiO Colloids ............................................. 62 2
2.4.2 Crystallization of Large Silica Spheres by Lifting and Stirring.............................. 63
2.4.3 Controlling of Silica Opal Quality .......................................................................... 64

3. Integration of 3D Photonic Crystals onto Structured Substrates ..................70
3.1 Fabrication of Patterned Silicon Substrates ................................................................... 71
3.2 Selective Crystallization................................................................................................. 72
3.3 Crystallization of Large SiO Spheres on Patterned Substrates..................................... 73 2
3.4 Characterization of Silica Opals on Patterned Substrates .............................................. 79
3.4.1 Fourier Transform Studies ...................................................................................... 79
3.4.2 Optical Measurements............................................................................................. 80
3.5 Influence of Substrate Structure on Crystallization ....................................................... 83
3.5.1 Opals in Trenches with Rectangular Shape and Smooth Sidewalls........................ 83
3.5.2 Opals in Trenches with Closed and Finite Shape Geometry................................... 87
3.6 Influence of Substrate Surface on Crystallization.......................................................... 89
3.6.1 LOCOS Substrate with Hydrophilic Bottoms and Sidewalls of Wells................... 89
3.6.2 SOI Substrate with Hydrophilic Bottoms and Hydrophobic Sidewalls of Wells ... 93
3.7 Crystallization of PMMA Spheres on Patterned Silicon Substrates .............................. 95
3.7.1 Factors of Precise Deposition of Spheres on Patterned Substrates ......................... 97
3.7.2 Optical Characterization of PMMA Opals on Patterned Silicon Substrates......... 102
3.7.3 Microspectroscopy Optical Analysis of Confined PMMA Crystals..................... 103
3.8 Crystallization of PMMA Spheres on Patterned Polymer Substrates.......................... 108

4. Multilayer Opals as Functionalized Photonic Crystals............................. 111
4.1 Fabrication of Triple-Film Opals from PMMA Spheres with Different Sizes ............ 112
4.2 Optical Characterization by UV-Vis Spectrometer...................................................... 120
4.3 TiO Sandwich Opals................................................................................................... 128 2



Contents III
5. Fabrications of Inverse Opals .............................................................. 136
®5.1 Inverse Opals from Inorganic-Organic Hybrid Polymer (ORMOCER ) .................... 137
®5.1.1 Fabrication of ORMOCER Replica .................................................................... 137
5.1.2 Structural Characterization by SEM Method ........................................................ 139
5.1.3 Optical Property of ORMOCER Replica.............................................................. 142
5.2 Fabrication of Silicon Replica on Patterned Substrates ............................................... 150
5.3 Inverse Opals as Catalyst Supports in Micro Reactors ................................................ 153

6. Summary.......................................................................................... 156

7. Experimental Part .............................................................................. 159
7.1 Syntheses of PMMA spheres ....................................................................................... 159
7.1.1 Preparation of PMMA spheres of a diameter smaller than 500 nm...................... 159
7.1.2 Preparation of PMMA spheres of a diameter larger than 500 nm ........................ 160
7.2 Fabrication of colloidal opals 161
7.2.1 Pre-treatment of substrates.................................................................................... 161
7.2.2 Preparation of PMMA opaline films..................................................................... 161
7.2.2.1 Horizontal crystallization ............................................................................... 161
7.2.2.2 Vertical crystallization ................................................................................... 162
7.2.3 Fabrication of silica opals from large size spheres ............................................... 162
7.2.3.1 Purification of the large SiO spheres ............................................................ 162 2
7.2.3.2 Crystallization of large silica spheres............................................................. 162
7.3 Fabrication of multilayer opals .................................................................................... 163
®7.4 Fabrication of ORMOCER replica............................................................................. 163
7.5 Characterization ........................................................................................................... 164
7.5.1 UV-Vis-Spectroscopy ........................................................................................... 164
7.5.2 Scanning electron microscopy (SEM)................................................................... 164

References 165
1. Introduction 1
1. Introduction

Photonic crystals are a class of materials with a periodic varying refractive index. Such
materials can create a range of ‘forbidden’ frequencies called a photonic bandgap (PBG), and
then they are well known as PBG materials. Photons with energies lying in the bandgap
cannot prop