Nanostructures and field emission propertiesof Alq3

• Main Author: 柯志忠
• Other Authors: 彭宗平
• Format: Others
• Language: en_US
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/77433935277425437015

碩士 === 國立清華大學 === 材料科學工程學系 === 90 === Abstract Key words: Nanotechnology, Scanning probe microscopy, carbon nanotubes, nanowires, organic light emitting diode, XRD, SEM, TEM, FTIR, PL , PM-NSOM A great deal of effort has been dedicated to the fundamental research of nanotechnology in the past 10 years. At the same time, the development of scanning probe microscopy, such as AFM and NSOM, has enabled the characterization of the nano scale. The investigation on the fabrication and application of nanostructured materials has attracted intensivel attention. The application in a flat panel display is regarded as one of the most promising applications of carbon nanotubes. Meanwhile, methods of synthesizing different species of nanowires have also been explored, and their field emission characteristics are one of the primary subject of study. A widely-used material of OLEDs, tris-(8-hydroxyquinolate)-aluminum (Alq3), is employed to fabricate nanowires in this study. Unlike traditional routes in preparing nanowires, such as the vapor-liquid-solid (VLS) process, an insert-gas evaporation method was applied to fabricate Alq3 nanowires on a liquid nitrogen-trapped substrate. Very few studies have been concentrated on the fabrication of organic nanowires before. In this work, the Alq3 nanowires can be readily produced at a relatively low temperature compared to the traditional routes for inorganic nanowires. From the x-ray diffraction patterns and TEM and SEM images, the partially amorphous nature and wire-like structure of Alq3 nanowires were described. Further identification of the Alq3 nanowires was conducted by means of FTIR, which evidenced that they were indeed composed of Alq3 molecules. The measurement of PL revealed a similar luminescence behavior of Alq3 nanowires to that of the bulk. The field emission characteristics showed a great possibility to apply the Alq3 nanowires to a flat panel display. In addition, a nano-optics technique, i.e., near-field scanning optical microscopy (NSOM), was employed to identify the crystalline nature of Alq3 film which was prepared in vacuum. AFM and SEM images showed a rod-like topography on the surface of the Alq3 film. A vibronic progression in the PL spectrum provided the evidence of crystallinity in film.