Sang Hern Lee

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Highly reflective and thermally stable indium-tin-oxide (ITO)-Ag-Pt p-type reflectors for use in high-performance GaN-based light-emitting diodes (LEDs) have been investigated. The specific contact resistance of the ITO-Ag-Pt contacts was found to be 7.2 &amp;times;10<sup>-5</sup>Omegamiddotcm<sup>2</sup>. The ITO-Ag-Pt contacts showed a higher reflectance(More)
We confirmed the potential of an aluminum nitride (AlN) substrate to be used as a bonding material for the high current operation of vertical light-emitting diodes (VLEDs). For the electrical connection to the top and bottom of the AlN substrate, via-holes were formed by laser drilling and then filled with Ag, which plays a role in improving the thermal(More)
Recent epidemiological studies have demonstrated that ginseng intake is associated with a reduced risk for environmentally related cancers. However, the effects of ginsenosides on the proliferation of renal proximal tubule cells have not yet elucidated. This study investigated the effect of total ginsenosides, protopanaxatriol (PT) saponin, and(More)
The enhancement of light extraction efficiency is observed when the hole-shape patterned ITO ohmic contact layer and AgIn reflector is adopted in GaN-based flip-chip (FC) light emitting diodes (LEDs). ITO layer (140 nm) and AgIn (200 nm) was deposited on the top of p-GaN by in-line DC sputtering and electron beam evaporating system, respectively. The ITO(More)
The periodic beveled micro-rods (BMRs) were constructed on the emission surface of GaN-based vertical light-emitting diodes (VLEDs) in order to improve the light-extraction efficiency. It was experimentally demonstrated that the light output power of the VLEDs with a periodic BMR (BMR-VLED) were enhanced about 15.6%, compared with that of the VLEDs with(More)
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