13 research outputs found
Study on growth morphology, microstructure, and magnetic properties of FePt/Pt alloy thin films
No full text학위논문(박사) - 한국과학기술원 : 물리학과, 2002.2, [ iv, 101, [4] p. ]한국과학기술원 : 물리학과
Commercial scale fabrication method for fabricating a gradient refractive-index rod: overcoming volume shrinkage and chemical restrictions
No full textWe report a fabrication method for a gradient refractive-index polymeric object from a binary comonomer system, regardless of the monomers' reactivity ratio and the molar volume criteria of gradient refractive-index development. To fabricate a large gradient refractive-index rod consisting of a methyl methacrylate and 2,2,3,3-tetrafluoropropyl methacrylate comonomer pair that has not been used for fabrication of a copolymer gradient refractive-index rod by previous conventional methods because of chemical restrictions in molar volume and reactivity ratio difference, we use the so-called successive UV polymerization in a controlled radial volume in conjunction with an automatic refill reactor. Simultaneously and automatically, the volume shrinkage problem, an inevitable shortcoming for the fabrication of a large polymeric object in a commercial production scale, is overcome and exploited. The theoretical features of the refractive-index profile generation of this method are also compared with those of conventional methods for which the chemical restrictions of monomers are crucial for the shape of a refractive-index profile. (c) 2006 Optical Society of America
Temperature dependence of growth morphology of sputtered (FePt/Pt) films on MgO (100) substrate
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Observation of perpendicular magnetic anisotropy in Ni/Pt multilayers at room temperature
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Hole-transporting interlayers for improving the device lifetime in the polymer light-emitting diodes
No full textThe authors report the effect of thermal treatment of hole-transporting interlayers between a polymeric hole injection layer and an emitting layer (EML) on the luminous efficiency and the lifetime performance in blue polymer light-emitting diodes. As the thermal annealing temperature of the interlayer increased, the hole mobility of the interlayer tended to decrease, which results in reducing the hole current injected into the EML in the devices. Hence, the device luminous efficiency decreased due to lower electron-hole balance. Nevertheless, the device lifetime increased, which can be attributed to the formation of the thicker interlayer and the better defined interlayer/EML interface.Y
Advancing the ferroelectric-based triboelectric nanogenerator via composition optimization
No full textThis work reports the vertical-contact mode triboelectric nanogenerator based on ferroelectric material, Bi0.5(Na1-xKx)0.5TiO3 where x}=0,0.18 (BNT-BKT). Various mixture ratios are used to find out the best materials composition. The low-cost Solid-state synthesis method synthesized high-quality BNT-BKT. Enhancement of electrical output of a ferroelectric material via doping another high dielectric constant material. Solid state reaction method was used for the materials fabrication. The BNT-BKT particles have a wide structural diversity and are lead-free, which can be further employed to make a composite film. A vertical contact-separate triboelectric nanogenerator device is fabricated, which can easily be assembled based on a composite film of PDMS and BNT-BKT polycrystalline particles. The voltage, current, and charge of the BNT-BKT/PDMS device were measured to be 291V}, 3.47\mu A}, and 42nC, respectively. The device is used for energy harvesting through LEDs and commercial watches. Further, we have reported a self-powered motion sensor. In the future, it can help with low-power healthcare sensors. © 2023 IEEE
A Study of Parasitic Series Resistance Components in In–Ga–Zn–Oxide (a-IGZO) Thin-Film Transistors
No full textDesigning a Stable Cathode with Multiple Layers to Improve the Operational Lifetime of Polymer Light‐Emitting Diodes
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