One-dimensional nanostructures for chemical sensing, transparent electronics, and energy conversion and storage devices

One-dimensional nanostructures have been intensively investigated and proven to be of great potential as building blocks in different applications, including nano/micro electronics, chemical/biological sensing, and more recently, energy conversion and storage devices. Nanowires and carbon nanotubes made from organic/inorganic methods are now available and give research opportunities for understanding of one-dimensional nanostructures and their future applications. In this field, the research can be divided into three categories: nanostructure synthesis, material characterizations, device fabrication for applications. These three main thrusts govern the research route to understand the one-dimensional nanostructures.;This dissertation follows above-mentioned elements and consists of eight chapters, which will mainly concentrate on three most promising applications based on one-dimensional nanostructures, including chemical sensing, transparent electronics, and electrochemical capacitors. Following an overview and an introduction of fundamental knowledge in one-dimensional nanostructures in Chapter 1, Chapter 2 and Chapter 3 will take up the application of one-dimensional nanostructures into the chemical sensing field. More specifically, Chapter 2 will carry out the important topic of "selectivity", which remains one of the challenging issues in the field, by using a nano electronic-nose sensor array built on four different one-dimensional nanostructures. The sensor array performs a great "discrimination power" and is capable to distinguish important industrial gases distinctly.;The detection of explosives and nerve agents are still one of missing blocks in current one-dimensional nanostructure based chemical sensors. Chapter 3 will introduce 2, 4, 6-trinitrotolune (TNT) sensors made of aligned single-walled carbon nanotubes (SWNTs) and ZnO nanowires. The discussion will primarily focus on the TNT sensing mechanism and the TNT sensing behavior of above two one-dimensional nanostructures.;Chapter 4 will concentrate on the synthesis of arsenic doped indium oxide (As-In2O3) nanowire and its application in the transparent electronics. A comprehensive study starting from nanowire synthesis, material characterizations, to electronic transport properties will be presented. In the end, a transparent integrated circuit, which uses nanowire transparent thin film transistors to control an active-matrix organic light emitting diode (AMOLED) display, will be fabricated and demonstrated.;Chapter 5 will provide a versatile approach to produce hybrid-nanostructured thin film electrodes by integrating transition-metal-oxide nanowires and SWNTs for the application in the electrochemical capacitors. Here, the detailed device fabrication of the first prototype of flexible and transparent supercapacitors will be presented, and the device performance will be examined and discussed later on.;Chapter 6 will present another prototype of supercapacitor, which are allowed a scalable fabrication and can be produced simply by utilizing a commercial inkjet printer. The electrochemical characterizations of the inkjet-printed SWNT thin film electrodes and the device performance of the first inkjet-printed supercapacitors will be discussed. Besides, another hybrid-nanostructured thin film electrode composed of ruthenium oxide (RuO 2) nanowires and SWNTs will be introduced to improve the device performance afterward.;In order to obtain high-performance supercapacitors with high power density and energy density to drive electrical vehicles, Chapter 7 will be dedicated to discuss the governing factors in aspects of the device structure and the choice of electrode materials. A hybrid device structures built on two different hybrid-nanostructured thin film electrodes will be adapted, and the detail of the electrode preparation, device fabrication and optimization, and the electrochemical performance will be examined and presented.;Chapter 8, in the end, summarizes the above discussions and proposes future research directions in one-dimensional nanostructures.