logo

korean english

게시판

Home > 게시판 > 세미나

아래와 같이 콜로퀴움을 개최하오니 많이 참석해 주시기 바랍니다. 아 래 1. 제목: ZnO nanorod heterostructures and nanodevices 2. 연사: 이 규 철 교수(포항공과대학교 신소재공학과) 3. 일시: 2006년 3월 31일(금요일) 오후 4시 30분 4. 장소: 물리학과 세미나실(31355호실) 5. 초록: One-dimensional nanorod heterostructures open up many new device applications, as already proven in thin film semiconductor electronics and photonics. As one of the semiconductor nanorod heterostructures, ZnO-based nanorod heterostructures have been studied and their synthesis and device applications will be presented in this talk. Recently, we developed catalyst-free metal-organic chemical vapor deposition of ZnO nanorods and employed these ZnO nanorods for electrical and optical nanodevice applications. In this presentation, I will discuss a couple of advantages of the catalyst-free method over metal catalyst assisted vapor-liquid-solid (VLS) method which has widely been used for growths of many kinds of semiconductor nanowires. First, the catalyst-free method excludes possible incorporation of metal impurities which may occur in the catalyst-assisted VLS methods, which enables to minimize unintentional impurity incorporation and offer high purity nanorods. As evidence of the high purity ZnO nanorod growth using the catalyst-free method, free exciton emission peaks was observed in PL spectra of ZnO nanorods measured at low temperatures below 15 K. The high purity materials growth makes it easy to control conductivity by doping and fabricate high performance devices. I will demonstrate fabrication of high performance field effect transistors based on the ZnO nanorods exhibiting high field effect electron mobility above 1000 cm2/Vs with a large turn ON/OFF ratio. Second, many kinds of nanorod heterostructures can be fabricated combining this catalyst-free method and conventional techniques already developed for growth of thin film heterostructure devices. For example, we demonstrated fabrications of metal/semiconductor nanorod heterostructures by simply evaporating metal on nanorod tips and nanorod quantum well structures and coaxial nanorod heterostructures by epitaxial growth. The heteroepitaxial nanostructures with well-defined crystalline interfaces are essential building blocks for the fabrication of devices on a single wire or a rod, which in principle permit extremely small size and ultrahigh density. Furthermore, embedding quantum structures in a single nanorod enable novel physical properties such as quantum confinement to be exploited, such as the continuous tuning of spectral wavelength by varying the well thickness. In this presentation, we demonstrate this to be the case by the fabrication of both ZnO/ZnMgO quantum well structures within individual ZnO nanorods and coaxial nanorod heterostructures. With precise thickness control down to the monolayer level, these heterostructures show the clear signature of quantum confinement, an increasing blue shift with decreasing layer thickness.
번호 제목 날짜 조회 수
공지 <12/8(Thu.) 11:00am>노벨상 소개 강연 - 2016년 노벨 물리학상: 위상 응집 물리의 탄생 2016.11.28 1079311
350 <Mar.28(Wed.) 4:30 PM>우주의 번개와 천둥 2018.03.27 45156
349 <May.30(Wed.) 4:30 PM> 구리산화물 고온 초전도체의 특성과 응용 2018.05.23 45458
348 <Dec.6(Wed.) 4:30 PM> 실험핵천체물리학: 과거와 미래(Experimental Nuclear Astrophysics: Past and Future) 2017.11.29 45592
347 <Nov.21(Wed.) 4:30 PM> 핵물리학과 RAON 2018.11.15 45686
346 <Mar.7(Wed.) 4:30 PM>Acoustic metamaterial: principles and applications of phononic crystals 2018.03.02 46128
345 <May.23(Wed.) 4:30 PM> 한국 희귀동위원소과학 프로젝트(Rare Isotope Science Project in Korea) 2018.05.16 46303
344 <Nov.29(Wed.) 4:30 PM> The Intensity Frontier Experiment & SHiP 2017.11.22 46352
343 <Nov. 1(Wed.) 4:30 PM> 광자와 이온트랩을 이용한 양자 정보처리 2017.10.25 46384
342 <Mar.21(Wed.) 4:30 PM>깊은 땅속 중성미자 실험, DUNE 2018.03.14 46545
341 <April.3(Wed.)> 전자구조계산을 이용한 새로운 양자물질 연구 2019.03.27 46794
340 2022학년도 1학기 콜로퀴움 일정 2022.01.10 46804
339 <Sep. 6(Wed.) 4:30 PM> Particles in the Universe 2017.09.01 47050
338 <Sep. 20(Wed.) 4:30 PM> 양자이론에 대한 `서울해석` 시도하기 2017.09.13 47288
337 <Sep. 13(Wed.) 4:30 PM> 우주론 100년, 어디로 가고 있는가? 2017.09.06 47837
336 <April.10(Wed.)> 자성 반데르발스 물질 발견과 전망(Discovery and Perspective of magnetic van der Waals materials) 2019.04.04 48247
335 <April.11(Wed.) 4:30 PM>History of Superconductivity and its Future 2018.04.04 49588
334 <Mar.10(Wed.)> Dark matter searches in neutrino detectors 2021.03.04 50699
333 <Oct. 11(Wed.) 4:30 PM> Graphene Membrane for Imaging Molecular Assembly and Dynamics 2017.09.27 50813
332 <June 7(Wed.) 4:30 PM> 물리학으로 보는 인간과 사회 2017.05.31 51160
331 <April. 12 (Wed.) 4:30 PM>디랙물질을 통해서 본 강상관 계의 양자 홀로그래피적 조명: 2017.04.05 51252