Controlling Growth In2Se3 Nanowires with RTA Process by VLS Mechanism and Phase Change Study of InSe Nanowires by Hydraulic Pressure Injection Method
| Autor: | Ya-Chu Ｈsu, 許雅筑 |
|---|---|
| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 Indium-selenide system is the mainly subject to discuss, diindium selenide (In2Se3) and indium monoselenide (InSe) are divided into two parts in this thesis. High uniformity Au-catalyzed In2Se3 nanowires are grown with the rapid thermal annealing (RTA) treatment via the vapor-liquid-solid (VLS) mechanism. The diameters of Au-catalyzed In2Se3 nanowires could be controlled with varied thickness of Au films and the uniformity of nanowires is improved via a fast pre-annealing rate, 100 °C/s. Comparing with the slower heating rate, 0.1 °C/s, the average diameters and distributions of In2Se3 nanowires that with and without RTA process are 97.14 nm ± 22.95 nm (23.63 %) and 119.06 nm ± 48.75 nm (40.95 %), respectively. The in-situ annealing TEM is used to study the effect of heating rate on the formation of Au nanoparticles from as-deposited Au film. The results demonstrate that the average diameters and distributions of Au nanoparticles that with and without RTA process are 19.84 nm ± 5.96 nm (30.00 %) and about 22.06 nm ± 9.00 nm (40.80 %), respectively. It proves that the diameter size, distribution and uniformity of Au-catalyzed In2Se3 nanowires are reduced and improved via the RTA pre-treated. The systemic study could help to control the size distribution of other nanomaterials through tuning the annealing rate, temperatures of precursor and growth substrate to control the size distribution of other nanomaterials. The highly ordered array of indium monoselenide (InSe) nanowires are fabricated by a hydraulic pressure injection processing with anodic aluminum oxide and microstructure is analyzed by templates. The morphology of InSe NWs was observed by SEM, XRD and Raman measurement. The temperature is the most important parameter for phase-change occurred. To observe the phenomenon of phase-change, thermal annealing processing of the InSe NWs was done under an in-situ heating TEM and ex-situ Raman analysis. The β-InSe is totally transformed to γ-In2Se3 happened as the temperature reaches to 700 °C. During proceeding the thermal processed, the α-In2Se3 will coexist with β-InSe till the β-InSe is totally transformed to γ-In2Se3. The CL spectrum confirmed that the direct band gap of InSe bulk is 1.24 eV. InSe bulk is temperature dependence of the energy gap. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|