DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | Chang, Kee-Joo | - |
dc.contributor.advisor | 장기주 | - |
dc.contributor.author | Kim, Yong-Sung | - |
dc.contributor.author | 김용성 | - |
dc.date.accessioned | 2011-12-14T07:23:13Z | - |
dc.date.available | 2011-12-14T07:23:13Z | - |
dc.date.issued | 2002 | - |
dc.identifier.uri | http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=177206&flag=dissertation | - |
dc.identifier.uri | http://hdl.handle.net/10203/47299 | - |
dc.description | 학위논문(박사) - 한국과학기술원 : 물리학과, 2002.8, [ [iv], 65 p. ] | - |
dc.description.abstract | On the basis of first-principles calculations, we present a structural model for the formation of H-induced (111) platelets in Si, which involves a structural transformation from a double-layer-$H_2^*$ configuration of $H_2^*$ aggregates into an H-saturated internal (111)-surface structure. This reaction process preferably occurs at high H plasma treatment temperatures, and subsequently generates H$_2$ molecules in the platelet voids, consistent with experiments. Our model also reveals the important features observed in (111) platelets, such as HRTEM images, step structures, lattice dilation lengths, and H vibrational frequencies. In GaAs, we find that substitutional nitrogens act as hydrogen traps, forming N-H complexes. For low H concentrations, we propose the formation of N-monohydride complexes, where H is positioned at a bond-center site between the N and one of the neighboring Ga atoms, explaining various experimental features such as the Fermi level dependence of the formation of N-H complexes, H vibrational frequencies, isotope shift, and photoconversion of the complexes. For very high H concentrations, the energetically favorable structure is a N-dihydride complex, which corresponds to a configuration of $H_2^*$ in the vicinity of N. This N-dihydride complex is optically inactive, suppressing N-related photoluminescence lines in N-containing GaAs, and induces a blue shift of the band gap in $GaAs_{1-x}N_x$ alloys. We investigate the stability of wurtzite and rocksalt $Mg_xZn_{1-x}O$ random alloys using a first-principles pseudopotential method within the local-density-functional approximation. From the calculated cohesive energies for Mg$_x$Zn$_{1-x}$O alloys in both the wurtzite and rocksalt structures, we find that the wurtzite phase is only stable for x<0.375. We propose that the solubility limit of Mg in wurtzite $Mg_xZn_{1-x}O$ alloys is about x = 0.375, close to the experimentally measured value of x = 0.33. The band gap ($E_{gap}$) is found to ... | eng |
dc.language | eng | - |
dc.publisher | 한국과학기술원 | - |
dc.subject | Si | - |
dc.subject | first-principles | - |
dc.subject | defect | - |
dc.subject | semiconductor | - |
dc.subject | GaAs | - |
dc.subject | 갈륨아세나이드 | - |
dc.subject | 실리콘 | - |
dc.subject | 제일원리 | - |
dc.subject | 결함 | - |
dc.subject | 반도체 | - |
dc.title | First-principles study of defect properties in semiconductors | - |
dc.title.alternative | 반도체 내의 결함 특성에 관한 제일원리 연구 | - |
dc.type | Thesis(Ph.D) | - |
dc.identifier.CNRN | 177206/325007 | - |
dc.description.department | 한국과학기술원 : 물리학과, | - |
dc.identifier.uid | 000995076 | - |
dc.contributor.localauthor | Kim, Yong-Sung | - |
dc.contributor.localauthor | 김용성 | - |
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