陳永芳臺灣大學：物理研究所吳冠儒Wu, Kuan-JuKuan-JuWu2007-11-262018-06-282007-11-262018-06-282007http://ntur.lib.ntu.edu.tw//handle/246246/54496Abstract In this thesis we report the study of optical and electrical properties on the composites based on liquid crystals and CdS nanorods. Quite interesting results have been obtained from our studies, which are very useful for the understanding as well as application of these materials. They are presented as follow. The novel nanocomposite device reveals a very unique and useful behavior that the polarization of the emission from semiconductor nanorods can be controlled by an external bias. The large magnitude of polarization anisotropy of 0.63 can be quantitatively interpreted very well in terms of the dielectric contrast between semiconductor and liquid crystal. Our approach is quite general, which is applicable to other nanomaterials, and it utilizes the currently mature liquid crystal display technology. The results open up new possible applications for one-dimensional semiconductor nanostructures in smart optoelectronic applications, including optical switches, integrated photonic devices, as well as electrochromatic gadgets in the near future.Contents List of Figures III List of Tables VIII 1. Introduction 1 2. Background 6 2. 1 Semiconductor nanowire (nanorod) 6 2.1.1 Characterization Of Semiconductor Nanowire 7 2.1.1.1 Transport Properties 7 2.1.1.2 Phonon-Transport Properties 7 2.1.1.3 Optical Properties 8 2.1.2 Device Application Of Semiconductor Nanowires 9 2.1.2.1 Electronic Devices 9 2.1.2.2 Light Emitting Devices 10 2.1.2.3 Photovoltaic Applications 11 2. 2 Liquid crystal (LCs) 11 2. 2. 1. Types of liquid crystal 11 2. 2. 1. 1 Calamitic Liquid Crystals 12 2. 2. 1. 2 Discotic Liquid Crystals 12 2. 2. 2 Basic physical properties of Liquid crystal 13 2. 2. 2. 1 Orientational order parameter 13 2. 2. 2. 2 Dielectric anisotropy 14 2. 2. 2. 3 Elastic constants 15 2. 2. 2. 4 Viscosity 16 2. 2. 3 Surface Alignment and Rubbing 17 2. 2. 4 Deformation of nematic liquid crystals by an electric field 18 2. 3 Micro-Photoluminescence 20 2. 3. 1 Principles and Applications of Micro-Photoluminescence 20 2. 3. 2 The Apparatus for Micro-Photoluminescence Measurement 23 3. CdS nanorods imbedded in liquid crystal cells for smart optoelectronic devices 44 3.1 Introduction 44 3.2 Experiment 45 3.2.1 Sample Preparation 45 3.2.2 Experiment setup and process 46 3.3 Results and Discussion 49 3.4 Summary 54 4. Conclusion 66en-US液晶硫化鎘liquid crystalCdSthesis