Study of III-nitride semiconductor heterostructures with ScN and graphene on silicon substrate
| Autor: | Shiu, Hung Wei, 許紘瑋 |
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| Rok vydání: | 2014 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 102 III-nitride semiconductors have attracted a lot of attention due to its outstanding electronic and optical properties for the application of optoelectronic devices. However, several effects strongly influence the performance of the III-nitride based devices, including natural spontaneous polarization, strain induced piezoelectric polarization, the substrate effects and heterostructure with other materials. In this study, two special materials for the heterostructures with GaN were introduced, one is ScN and the other is graphene. ScN is a non-polar material and its lattice parameter is excellently matched with GaN, using ScN as a buffer layer for growing GaN will definitely enhance the quality of GaN. Moreover, graphene is one of the best candidates to be used as transparent electrode for III-nitride semiconductor based optical devices, because of its marvelous transparency and electronic properties. In addition to the heterostructures, the intrinsic properties of III-nitride semiconductor itself are also important, especially for the unusual surface properties of InN. Accordantly, it is interesting to investigate the electronic properties and crystalline structure of these nitride semiconductors and its heterostructure with the proposed buffer layer of ScN and top electrode of graphene. In Chapter 1, the basic properties of III-nitride semiconductors, rare-earth materials and graphene based optical and electronic devices will be introduced. Chapter 2 briefly describes the related experimental methods used in this study. Previous studies indicated when growing ScN on Si, a small amount of Sc silicides might form at the interface. Therefore, in Chapter 3.1, properties of Sc silicide overlayer on Si (111) substrate will be discussed, then the electronic and crystalline structures and the corresponding band line-up of ScN/GaN heterostructure will be presented in Chapter 3.2. Chapter 4 describes the layer number dependent optical and electronic properties of the device applications by using graphene as a transparent electrode on GaN surface. In Chapter 5, a fundamental study of in situ grown InN surface will be presented, in an attempt to understand the strong electron accumulation effect occurred in InN surface. Finally, Chapter 6 summarizes and pictures the future perspective of this study |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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