• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.04a
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• pp.51-52
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• 2008

A single gap transflective liquid crystal display(LCD) driven by fringe electric field in the transmissive(T) region and vertical electric field in the reflective(R) region was designed. Because the pretilt angle is formed in $53^{\circ}$ through polymerization of an UV curable reactive mesogen(RM) monomer at the surface, the effective cell retardation $(d{\Delta}n_{eff})$ value of the R region becomes half of that in the T region where the LCs are homogenously aligned. Consequently, a transflective display driven by a vertical and fringe electric field with a single cell gap and single gamma curves is realized.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.2
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• pp.152-155
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• 2011

Even though nano-scale materials were very advantageous for various applications, there are still problems to be solved such as the stabilization of surface state and realization of low contact resistances between a semiconducting nanowire and electrodes in nano-electronics. It is well known that the effects of contacts barrier between nano-channel and metal electrodes were dominant in carrier transportation in individual nano-electronics. In this report, it was investigated the electrical properties of GaN nanorod devices after chemical etching and rapid thermal annealing for making good contacts. After KOH wet-etching of the contact area the devices showed better electrical performance compared with non-treated GaN individual devices but still didn't have linear voltage-current characteristics. The shape of voltage-current properties of GaN devices were improved remarkably after rapid thermal annealing as showing Ohmic behaviors with further bigger conductivities. Even though chemical etching of the nanorod surfaces could cause scattering of carriers, in here it was shown that the most important and dominant factor in carrier transport of nano-electronics was realization of low contact barrier between nano-channel and metal electrodes surely.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.180-180
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• 2010

본 연구에서는 P-Type의 NiO를 Glass기판의 ITO전극위에 RF-스퍼터링 방법으로 증착하였으며, NiO 완충층의 두께 변화에 따른 OLED (Organic Light Emitting Diode) 소자의 발광 특성에 대해 연구하였다[1, 2]. NiO는 우수한 전기 광학적 특성을 가지고 있어 OLED소자의 구동전압, 발광 효율 등의 특성을 향상 시킬 수 있다[3]. NiO 완충층의 두께 변화는 스퍼터링 증착시간을 통해 5-20 nm로 조절하였으며 소자의 구조는 Glass/ITO/NiO(0~20nm)/NPB(40nm)/Alq3(60nm)/LiF(0.5nm)/Al(120nm)형태로 제작하였다. ITO/NPB 계면에 NiO 완충층을 삽입함으로써 OLED 발광소자의 구동전압을 ~8V에서 ~5V (NiO, 10nm)로 낮출 수 있었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.3-4
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• 2005

Germanium nanocrystals(NCs) were formed in the silicon dioxide($SiO_2$) on Si layers by Ge implantation and rapid thermal annealing process. The density and mean size of Ge-NCs heated at $800^{\circ}C$ during 10 min were confirmed by High Resolution Transmission Electron Microscopy. Capacitance versus voltage(C-V) measurements of MOS capacitors with single $Al_2O_3$ capping layers were performed in order to study electrical properties. The C-V results exhibit large threshold voltage shift originated by charging effect in Ge-NCs, revealing the possibility that the structure is applicable to Nano Floating Gate Memory(NFGM) devices.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.171-171
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• 2011

Co and Fe doped multi-wall carbon nano-tubes (MWCNTs) synthesized by microwave plasma enhanced chemical vapor deposition (PECVD) technique are investigated with synchrotron radiations at Pohang Light Source (PAL) and European Synchrotron Radiation Facility (ESRF). Near edge x-ray absorption spectroscopy (NEXAFS) measurement at C K, Co $L_{3,2}$ and Fe $L_{3,2}$-edges, and x-ray magnetic circular dichroism (XMCD) at Co and Fe $L_{3,2}$-edges have been carried at 7B1 XAS KIST and 2A MS beamline, respectively, to understand the electronic structure and responsible magnetic interactions at room temperature. X-ray absorption spectroscopy (XAS) at C K-edge shows significant p-bonding and Co and Fe L-edges proves the presence of $Co^{2+}$ and $Fe^{2+}$ in octahedral symmetry. Co and Fe doped MWCNTs show good XMCD spectra at 300K. The effect on the magnetism is also studied through swift heavy ion (SHI) radiations and magnetism is found enhanced and change in the electronic structure in Co-CNTs is investigated.

• Advances in nano research
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• v.8 no.1
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• pp.13-24
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• 2020

In this paper, for the first time based on the nonlocal strain gradient theory the effect of size dependency in torsional vibration of bi-direction functionally graded (FG) nonlinear nano-cone is study. The material properties were assumed to vary according to the arbitrary function in radial and axial directions. The Navier equation and boundary conditions of the size-dependent bidirectional FG nonlinear nano-cone were derived by Hamilton's principle. These equations were solved by employing the generalized differential quadrature method (GDQM). The presented model can turn into the classical model if the material length scale parameters are taken to be zero. The effects of some parameters, such as inhomogeneity constant, cross-sectional area parameter and small-scale parameters, were studied. As an essential result of this study can be stated that an FG nano-cone model based on the nonlocal elasticity theory behaves softer and based on the strain gradient theory behaves harder.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.6
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• pp.1-6
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• 2018

Recently nano meter size pattern (sub-micro scale) can be machined mechanically using a diamond tool. Many studies have found a 'size effect' which referred to a specific cutting energy increase with the decrease in the uncut chip thickness at micro scale machining. A new analysis method was suggested in order to observe 'size effect' in nano scale machining and to verify the cause of the 'size effect' in this study. The diamond tool was indented to a vertical depth of 1,000nm depth in order to simplify the stress state and the normal force was measured continuously. The tip rounding was measured quantitatively by AFM. Based on the measurements and theoretical analysis, it was verified that the main cause of the 'size effect' in nano scale machining is geometrically necessary dislocations, one of the intrinsic material characteristics. st before tool failure.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.6
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• pp.556-562
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• 2023

This paper presents the development and market trends of nano biosensors. These biosensors must possess high sensitivity and selectivity to effectively detect diseases. Presently, many research groups are focusing on the field-effect transistor aspect of nano biosensors, which can identify diseases such as Down syndrome, bladder cancer, breast cancer, and numerous other cancers, utilizing graphene and transition metal dichalcogenide materials. In the case of in-vitro diagnostics, the use of nano biosensors has been rapidly growing since the onset of the COVID-19 pandemic. This paper also discusses market trends and the outlook for both national and international enterprises engaged in the nano biosensor field. Nano biosensors are expected to play a beneficial and significant role soon, contributing to the early diagnosis of diseases and subsequently improving patient outcomes.

• Korean Journal of Optics and Photonics
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• v.28 no.6
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• pp.356-360
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• 2017

Indium tin oxide (ITO) provides high electrical conductivity and transparency at visible and near-IR wavelengths. ITO is widely used as a transparent electrode for the fabrication of LCDs, OLEDs, and many kinds of optical applications. It is widely employed for electrodes in various electric and display sectors because of its transparency in the visible range and high conductivity. Therefore, one issue is removing a specific area of a layer of material such as ITO or metallic film on a substrate, without affecting the properties of the substrate. ITO-on-glass removal using a laser is friendlier to the environment than traditional methods. In this study, ablation of ITO film on glass using a femtosecond-laser micromachining system (wavelength 1026 nm, pulse duration 150 fs) and a nanosecond-laser micromachining system (wavelength 1027 nm, pulse duration 5 ns) are described, compared, and analyzed.

• Korean Journal of Crystallography
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• v.16 no.1
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• pp.11-20
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• 2005

Six basic symmetries and five Bravais lattices existing in the two-dimensional lattice are derived and then ten two-dimensional point groups are classified by each of five Bravais lattices. Finally seventeen two-dimensional space groups belonging to the ten point groups are studied.