http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
5G 및 수상드론을 통한 울산항 안전운항 관리 솔루션 및 가상현실 시뮬레이션
김성연 ( Seongyeon Kim ),김연진 ( Yeonjin Kim ),김정수 ( Jeongsu Kim ),황준호 ( Jhunho Hwang ),김정민 ( Jeongmin Kim ) 한국정보처리학회 2020 한국정보처리학회 학술대회논문집 Vol.27 No.2
전체 해양 사고 원인 중 선박 운항 부주의가 34%로 사고 발생 원인 중 대다수를 차지한다. 해당 문제를 해결하기 위해서는 선박 운항자를 대상으로 효과적인 운항 교육 및 실시간 관제 시스템을 제공해 사고를 방지하는 것이 중요하다. 따라서 울산항만을 현실적으로 반영한 가상현실 시물레이션 및 5g 수상드론을 이용한 운항 교육 시스템과 모든 선박들이 사용가능한 실시간 관제 시스템을 연구하고 이를 울산 항만에 제공한다.
Converting a Host Receptor into Sustained Intranasal Virucides against SARS-CoV-2 Using Nanodiscs
Jaehyeon HWANG,Wonbeom PARK,Soomin KIM,SeungJoo KIM,Suhyun KIM,Nayoon CHOI,Eunkhang PARK,Hwanju KIM,Mina KIM,Hyunjoo CHOO,Soyun CHOI,MinKyeom KIM,YeonJin CHO,Dae-Hyuk KWEON 한국생물공학회 2023 한국생물공학회 학술대회 Vol.2023 No.10
Observation of tunable band gap and anisotropic Dirac semimetal state in black phosphorus
Kim, Jimin,Baik, Seung Su,Ryu, Sae Hee,Sohn, Yeongsup,Park, Soohyung,Park, Byeong-Gyu,Denlinger, Jonathan,Yi, Yeonjin,Choi, Hyoung Joon,Kim, Keun Su American Association for the Advancement of Scienc 2015 Science Vol.349 No.6249
<P><B>Tuning the band gap of black phosphorus</B></P><P>Most materials used in electronics are semiconductors. The sizable energy gap in their electronic structure makes it easy to turn the conduction of electricity on and off. Graphene naturally lacks this band gap unless it undergoes certain modifications. Kim <I>et al.</I> studied the electronic structure of black phosphorus—a related two-dimensional material. By sprinkling potassium atoms on top of single layers of black phosphorus, the material changed from being a semiconductor to having a gapless linear dispersion similar to that of graphene.</P><P><I>Science</I>, this issue p. 723</P><P>Black phosphorus consists of stacked layers of phosphorene, a two-dimensional semiconductor with promising device characteristics. We report the realization of a widely tunable band gap in few-layer black phosphorus doped with potassium using an in situ surface doping technique. Through band structure measurements and calculations, we demonstrate that a vertical electric field from dopants modulates the band gap, owing to the giant Stark effect, and tunes the material from a moderate-gap semiconductor to a band-inverted semimetal. At the critical field of this band inversion, the material becomes a Dirac semimetal with anisotropic dispersion, linear in armchair and quadratic in zigzag directions. The tunable band structure of black phosphorus may allow great flexibility in design and optimization of electronic and optoelectronic devices.</P>
Yeonjin Je,Eunjeong Kim,Nguyen Vu Binh,Hyeongtae Kim,Su-yeon Cho,Do-Hyeon Lee,Mi Ji Kwon,Moonhee Choi,Jae Hyun Lee,Woo Hyun Nam,Younki Lee,Jung Young Cho,Jun Hong Park 대한금속·재료학회 2023 ELECTRONIC MATERIALS LETTERS Vol.19 No.5
Since the emergence of layered two-dimensional materials, the development of methods for their large-scale synthesis has become crucial for integrating these materials into existing fabrication processes. In this study, we report the synthesis of a NiTe 2 single crystal on the near-centimeter scale using the molten salt fl ux method (MSFM). The single-crystal nature of the synthesized NiTe 2 sample was confi rmed using X-ray diff raction analysis, while its chemical characteristics were analyzed using X-ray photoelectron spectroscopy, which confi rmed Ni–Te chemical binding. The layered structure of the ingot was confi rmed using Raman spectroscopy; two prominent signals were observed, at 84 and 138 cm −1 , which were consistent with the in-plane vibrational mode, E g , and out-of-plane vibrational mode, A 1g . In addition, analyses performed on diff erent fl akes confi rmed the structural uniformity of the single crystal, as only a small variation in the peak-to-peak position of the full width at half maximum was observed. Using Kelvin probe force microscopy, the electronic structure of the NiTe 2 multilayered surface was investigated to determine its surface work function, which was found to be 4.4–4.8 eV. A back-gate fi eld-eff ect transistor was fabricated using the single-crystal NiTe 2 to evaluate its semimetallic characteristics; the transfer characteristic of the NiTe 2 FET, determined by applying a back-gate bias, showed weak gate voltage dependence and linear I–V characteristics, in keeping with the linear I D -V D output characteristics. Therefore, the synthesis of NiTe 2 via the MSFM should facilitate the integration of layered materials with existing fabrication processes for the mass production of electronic devices.
Direct p-doping of Li-TFSI for efficient hole injection: Role of polaronic level in molecular doping
Kim, Kiwoong,Jeong, Junkyeong,Kim, Minju,Kang, Donghee,Cho, Sang Wan,Lee, Hyunbok,Yi, Yeonjin Elsevier 2019 APPLIED SURFACE SCIENCE - Vol.480 No.-
<P><B>Abstract</B></P> <P>Bis(trifluoromethane)sulfonimide lithium salt (Li-TFSI) has been popularly employed as an efficient p-dopant that increases the conductivity of a hole transport layer (HTL) in perovskite solar cells and dye-sensitized solar cells. However, the working mechanism of the Li-TFSI dopant is a long-standing question. The hygroscopicity of Li-TFSI makes it difficult to isolate the exact doping mechanism. In this study, we unveil the role of Li-TFSI in the p-doping to the <I>N</I>,<I>N</I>′-di(1-naphthyl)-<I>N</I>,<I>N</I>′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) HTL. A series of systematic in situ measurements using ultraviolet and inverse photoelectron spectroscopy reveal that electron transfer from NPB to Li-TFSI occurs due to the lower-lying negative polaronic level of Li-TFSI rather than the positive polaronic level of NPB. The hole injection barrier between NPB and indium tin oxide is significantly reduced with Li-TFSI doping, enhancing the device performance of hole-only devices and organic light-emitting diodes dramatically. With excessive dopants, however, the agglomerative property of Li-TFSI became dominant, decreasing the doping efficiency. These results provide robust guidelines for developing an efficient doping method for a molecular system with high conductivity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Electronic structure of Li-TFSI and NPB was investigated using in situ UPS and IPES. </LI> <LI> Electron transfer occurred from NPB to Li-TFSI through their polaronic levels. </LI> <LI> Hole injection barrier was reduced by 0.70 eV with Li-TFSI doping. </LI> <LI> Device performance of OLEDs was significantly enhanced with Li-TFSI doping. </LI> <LI> With excessive dopants, agglomeration of Li-TFSI decreased doping efficiency. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Kim, Tae Gun,Lee, Hyunbok,Yi, Yeonjin,Lee, Seung Mi,Kim, Jeong Won American Institute of Physics 2015 Journal of Applied Physics Vol.118 No.2
<P>A three layer cathode is a promising stack structure for long lifetime and high efficiency in organic light-emitting diodes. The interfacial chemical reactions and their effects on electronic structures for alkaline-earth metal (Ca, Ba)/Alq(3) [tris(8-hydroxyquinolinato) aluminum] and Ca/BaF2/Alq(3) are investigated using in-situ X-ray and ultraviolet photoelectron spectroscopy, as well as molecular model calculation. The BaF2 interlayer initially prevents direct contact between Alq(3) and the reactive Ca metal, but it is dissociated into Ba and CaF2 by the addition of Ca. As the Ca thickness increases, the Ca penetrates the interlayer to directly participate in the reaction with the underlying Alq(3). This series of chemical reactions takes place irrespective of the BaF2 buffer layer thickness as long as the Ca overlayer thickness is sufficient. The interface reaction between the alkaline-earth metal and Alq(3) generates two energetically separated gap states in a sequential manner. This phenomenon is explained by step-by-step charge transfer from the alkaline-earth metal to the lowest unoccupied molecular orbital states of Alq(3), forming new occupied states below the Fermi level. (C) 2015 AIP Publishing LLC.</P>