SCREW-DISLOCATION-DRIVEN GROWTH MODE AND OPTICAL PROPERTIES OF TWO-DIMENDIONAL GALLIUM SELENIDE ON GALLIUM ARSENIDE (001) BY MOLECULAR BEAM EPITAXY
| Autor: | NHU QUYNH DIEP, 葉如瓊 |
|---|---|
| Rok vydání: | 2019 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 107 Regardless of the dissimilarity in their crystal symmetry, the two-dimensional GaSe of different structure phases grown on GaAs(001) substrates by molecular beam epitaxy reveal a screw-dislocation-driven growth mechanism. Attributing to this mechanism, the spiral-pyramidal structure of 2D GaSe layers was typically observed. Investigations on Raman spectroscopy and temperature-dependent photoluminescence indicated that the structure has been suffered an amount of in-plane tensile strain due to the stacking disorders between monolayer at the boundaries of the 2D GaSe nanoflakes as well as the screw-dislocation-driven growth mode. In addition, Raman spectra under various wavelength laser excitations explored the common ε-phase of 2D GaSe materials grown directly on GaAs(001) which can be transformed into the β-phase by introducing a Se-pretreatment period at the initial growth process. This work provides an understanding of MBE growth of 2D layered materials on three-dimensional substrates and paves the way to realize future electronic and optoelectronic heterogeneous integrated technology as well as second harmonic generation applications. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|