logo

korean english

게시판

Home > 게시판 > 세미나

양자물질초전도연구실에서 세종대학교 홍석륜 교수님을 초청하여 아래와 같이 세미나를 개최합니다.

학과 구성원 여러분의 많은 참여를 부탁 드립니다.

온라인으로 진행되는 세미나입니다.

===========================================================================

Title: Electronic Properties of Mixed-dimensional 2D/3D Heterostructures


Speaker: 홍  석  륜  교수님 (세종대학교)


Date/time: 2021. 8. 4. (Wed.) 4:00PM


○ 온라인 참여방법: 아래의 WebEx 링크 접속

https://skku-ict.webex.com/meet/tp8701


Abstract: Graphene and other 2D materials such as transition metal dichalcogenides (TMDs) and metal monochalcogenides (MMCs) have attractive physical and chemical properties. For utilization of 2D materials as electronic devices, their mixed-dimensional van der Waals (vdW) heterostructures with 3D materials are receiving much attention. To understand electronic properties of these mixed-dimensional 2D/3D heterostructures, we have performed density functional theory calculations.
We investigate the reduction of the Fermi level pinning (FLP) at Au–MoS2 interfaces by atomic passivation on Au(111). Passivating atoms prevent the direct contact between Au(111) and MoS2, and thus FLP at Au–MoS2 interfaces is reduced by weak interaction between atom-passivated Au(111) and MoS2. Especially, FLP is greatly reduced at sulfur-passivated Au-MoS2 interfaces with the smallest binding energy. Furthermore, fluorine-passivated Au(111) can form ohmic contact with MoS2, representing almost zero Schottky barrier height (SBH). We suggest that SBH can be controlled depending on the passivating atoms on Au(111).
Next, we study atomic and electronic structures of the 2D/3D heterojunction between MoS2 and Si(100) by focusing on the contact behavior dependence on the interfacial structures. Calculations show that MoS2 and clean Si(100) form an almost n-type ohmic contact with small SBH due to strong covalent bonds between them, and that the contact between MoS2 and H-Si(100) makes a p–n heterojunction with weak vdW interactions. Such a difference in contact behaviors can be explained by different electric dipole formation at the heterojunction interfaces. Similarly, 2D/3D heterostructures between GaSe and Si(111) are investigated. GaSe forms n-type contact with c-Si(111) and thus Fermi level pinning occurs at GaSe/c-Si(111) interfaces with metal-induced gap states. In the case of GaSe/H-Si(111), we identify that the interfaces form p-n heterojunction, especially with type II band alignment. Overall, it is concluded that contact properties can be varied depending on the interfacial structures of 2D/3D semiconductor heterojunctions.

번호 제목 날짜 조회 수
공지 <12/8(Thu.) 11:00am>노벨상 소개 강연 - 2016년 노벨 물리학상: 위상 응집 물리의 탄생 2016.11.28 1058671
16 <May 04(Tue.)>Flat bands and the geometry of Bloch wave function 2021.04.27 66830
15 <June 01(Tue.)>Frustration-induced Athermal Behaviors: Hilbert Space Fragmentation and Quantum Many-Body Scars 2021.05.24 38118
14 <June 10(Thu.)>Oxide electronics utilizing spin-orbit coupling 2021.05.31 152022
13 <June 23(Wed.)>Valley Polarization and Exciton Hall Effect in Transition Metal Dichalcogenides 2021.06.22 26983
12 <June 30(Wed.)>Mapping of magnetic anisotropy for van der Waals materials 2021.06.25 72288
11 <July 7(Wed.)>Functional rare earth ionic defects and the related phenomena 2021.07.02 85463
10 <July 14(Wed.)> B1g phonon anomaly driven by Fermi surface instability at intermediate temperature in YBa2Cu3O7−δ 2021.07.13 37071
9 <July 21(Wed.)> Strongly Correlative Ionics 2021.07.19 22412
8 <Aug. 6(Fru.)> Gravitationally probing dark matter (DM) microphysics 2021.08.03 26269
» <Aug. 4(Wed.)>Electronic Properties of Mixed-dimensional 2D/3D Heterostructures 2021.08.04 69833
6 <Nov. 5(Fri.)>Strongly Coupled Moire Photonics 2021.11.01 36353
5 <Nov. 29(Mon.)>Exploring light-matter interactions at atomic scale using electron microscopy 2021.11.22 6620
4 <Jan. 27(Thu.)>Emulating twisted double bilayer graphene with a multiorbital optical lattice 2022.01.18 2307
3 <May. 3(Tue.)>Anomalous Hall signatures of nonsymmorphic nodal lines in the doped chromium chalcospinel CuCr2Se4 2022.04.19 1404
2 <May. 10(Tue.)>Longitudinal magnon decay in the quasi-two-dimensional antiferromagnet in Ba2FeSi2O7 2022.05.09 1298
1 <July 8(Fri.)>Intertwined magnetism and charge density wave in a kagome metal 2022.06.03 906