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.

Flexible Inorganic Nanostructure Light-Emitting Diodes Fabricated on Graphene Films

Abstract: Organic materials [ 1 , 2 ] and amorphous fi lms [ 3 ] have long been studied for foldable and wearable mobile devices since the devices must be fabricated on a fl exible plastic fi lm. However, higher device performance is expected using a singlecrystalline inorganic compound semiconductor, such as gallium nitride (GaN), because of its high radiative recombination rate and mobility, as well as its excellent thermal and mechanical characteristics. [ 4 ] Nevertheless, the high growth temperatures of single-crystalline inorganic semiconductors make it diffi cult to use a conventional plastic substrate with a low melting temperature. In addition, a continuous, rigid inorganic fi lm has little tolerance for mechanical deformation. Although such problems can be circumvented by using assembly methods of micrometre-scale inorganic devices, [ 5–7 ] complicated processes including many lithography and etching steps are required for fabricating and assembling the devices. These obstacles can be overcome basically using inorganic nanostructures grown on graphene fi lms, which exhibit high temperature compatibility and good mechanical fl exibility. Here, we report on the fabrication of fl exible inorganic light-emitting diodes (LEDs) using GaN/ZnO coaxial nanorod heterostructures grown directly on graphene fi lms and their reliable operation. The basic strategy for the heteroepitaxial growth of GaN/ ZnO coaxial nanorod heterostructures on graphene fi lms and

Search for the associated production of the Higgs boson with a top-quark pair

Abstract: A search for the standard model Higgs boson produced in association with a top-quark pair (ttH) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb^(−1) and 19.7 fb^(−1) collected in pp collisions at center-of-mass energies of 7 TeV and 8 TeV respectively. The search is based on the following signatures of the Higgs boson decay: H → hadrons, H → photons, and H → leptons. The results are characterized by an observed ttH signal strength relative to the standard model cross section, μ=σ/σ SM,under the assumption that the Higgs boson decays as expected in the standard model. The best fit value is μ = 2.8 ± 1.0 for a Higgs boson mass of 125.6 GeV.

Unoxidized Graphene/Alumina Nanocomposite: Fracture- and Wear-Resistance Effects of Graphene on Alumina Matrix

Abstract: It is of critical importance to improve toughness, strength, and wear-resistance together for the development of advanced structural materials. Herein, we report on the synthesis of unoxidized graphene/alumina composite materials having enhanced toughness, strength, and wear-resistance by a low-cost and environmentally benign pressure-less-sintering process. The wear resistance of the composites was increased by one order of magnitude even under high normal load condition (25 N) as a result of a tribological effect of graphene along with enhanced fracture toughness (KIC) and flexural strength (σf) of the composites by ~75% (5.60 MPa·m1/2) and ~25% (430 MPa), respectively, compared with those of pure Al2O3. Furthermore, we found that only a small fraction of ultra-thin graphene (0.25–0.5 vol%, platelet thickness of 2–5 nm) was enough to reinforce the composite. In contrast to unoxidized graphene, graphene oxide (G-O) and reduced graphene oxide (rG-O) showed little or less enhancement of fracture toughness due to the degraded mechanical strength of rG-O and the structural defects of the G-O composites.