| Summary: | 碩士 === 國立清華大學 === 材料科學工程學系 === 92 === Organic materials are considered as a promising field in the 21st century. The vigorous development in nanoscience and nanotechnology is based on a complete research of a nanostructured materials. The present study is a succession to the previous work on Alq3 organic nanoparticles.
The size of Alq3 nanoparticles prepared by a vapor condensation can be altered by controlling working pressure, working temperature, substrate temperature, and distance between the boat and the substrate. The helix cross-linked morphology observed by SEM and the formation and growth mechanism could be explained by the principles of atmospheric science and meteorology. The amorphous structure of Alq3 nanoparticles was examined by XRD, TEM, and transmittance spectra. By DSC measurement the phase transition temperature and the melting point was found to decrease due to the nanosized structure. The moisture and oxygen sensitivity of Alq3 nanoparticles with different sizes were studied by photoluminescence spectra (PL). The result shows that the degradation rate increases as the particle size decreases.
Besides, the annealing process made the nanoparticles become partially crystallized. The morphology was changed into nanowires with a diameter close to the particle size and a length longer than 1 μm. This provides a new route to prepare nanowires of Alq3. The peaks of PL spectra showed a blue shift as the amorphous nanoparticles transformed into crystalline nanowires, and the crystalline phase can be identified by transmittance spectrum.
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