Sungkyunkwan University

About: Sungkyunkwan University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Thin film & Graphene. The organization has 28229 authors who have published 56428 publications receiving 1352733 citations. The organization is also known as: 성균관대학교.

Searches for Sterile Neutrinos with the IceCube Detector.

Abstract: The IceCube neutrino telescope at the South Pole has measured the atmospheric muon neutrino spectrum as a function of zenith angle and energy in the approximate 320 GeV to 20 TeV range, to search for the oscillation signatures of light sterile neutrinos. No evidence for anomalous ν_{μ} or ν[over ¯]_{μ} disappearance is observed in either of two independently developed analyses, each using one year of atmospheric neutrino data. New exclusion limits are placed on the parameter space of the 3+1 model, in which muon antineutrinos experience a strong Mikheyev-Smirnov-Wolfenstein-resonant oscillation. The exclusion limits extend to sin^{2}2θ_{24}≤0.02 at Δm^{2}∼0.3 eV^{2} at the 90% confidence level. The allowed region from global analysis of appearance experiments, including LSND and MiniBooNE, is excluded at approximately the 99% confidence level for the global best-fit value of |U_{e4}|^{2}.

Low-Temperature Ohmic Contact to Monolayer MoS2 by van der Waals Bonded Co/h-BN Electrodes

Abstract: Monolayer MoS2, among many other transition metal dichalcogenides, holds great promise for future applications in nanoelectronics and optoelectronics due to its ultrathin nature, flexibility, sizable band gap, and unique spin-valley coupled physics. However, careful study of these properties at low temperature has been hindered by an inability to achieve low-temperature Ohmic contacts to monolayer MoS2, particularly at low carrier densities. In this work, we report a new contact scheme that utilizes cobalt (Co) with a monolayer of hexagonal boron nitride (h-BN) that has the following two functions: modifies the work function of Co and acts as a tunneling barrier. We measure a flat-band Schottky barrier of 16 meV, which makes thin tunnel barriers upon doping the channels, and thus achieve low-T contact resistance of 3 kΩ.μm at a carrier density of 5.3 × 1012/cm2. This further allows us to observe Shubnikov–de Haas oscillations in monolayer MoS2 at much lower carrier densities compared to previous work.

Observation of Energy and Baseline Dependent Reactor Antineutrino Disappearance in the RENO Experiment.

Abstract: The RENO experiment has analyzed about 500 live days of data to observe an energy dependent disappearance of reactor ν[over ¯]_{e} by comparing their prompt signal spectra measured in two identical near and far detectors In the period between August of 2011 and January of 2013, the far (near) detector observed 31 541 (290 775) electron antineutrino candidate events with a background fraction of 49% (28%) The measured prompt spectra show an excess of reactor ν[over ¯]_{e} around 5 MeV relative to the prediction from a most commonly used model A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the observed number of ν[over ¯]_{e} Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0082±0009(stat)±0006(syst) and |Δm_{ee}^{2}|=[262_{-023}^{+021}(stat)_{-013}^{+012}(syst)]×10^{-3} eV^{2}

High-performance n-type black phosphorus transistors with type control via thickness and contact-metal engineering

Abstract: Recent work has demonstrated excellent p-type field-effect switching in exfoliated black phosphorus, but type control has remained elusive. Here, we report unipolar n-type black phosphorus transistors with switching polarity control via contact-metal engineering and flake thickness, combined with oxygen and moisture-free fabrication. With aluminium contacts to black phosphorus, a unipolar to ambipolar transition occurs as flake thickness increases from 3 to 13 nm. The 13-nm aluminium-contacted flake displays graphene-like symmetric hole and electron mobilities up to 950 cm2 V−1 s−1 at 300 K, while a 3 nm flake displays unipolar n-type switching with on/off ratios greater than 105 (107) and electron mobility of 275 (630) cm2 V−1 s−1 at 300 K (80 K). For palladium contacts, p-type behaviour dominates in thick flakes, while 2.5–7 nm flakes have symmetric ambipolar transport. These results demonstrate a leap in n-type performance and exemplify the logical switching capabilities of black phosphorus. Black phosphorus p-type field-effect switching was previously demonstrated, but type control has proven difficult. Here, the authors create n-type black phosphorus Schottky field-effect transistors in which the polarity is controlled via contact-metal engineering and changing the flake thickness.