Hyun Kyong Cho

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The nano-imprint lithography method was employed to incorporate wide-area (375 x 330 mum(2)) photonic-crystal (PC) patterns onto the top surface of GaN-based LEDs. When the 280-nm-thick p-GaN was partly etched to ~140 nm, the maximal extraction-efficiency was observed without deteriorating electrical properties. After epoxy encapsulation, the light output(More)
The effect of aminoguanidine hydrochloride (AG) on the blood-retinal barrier was studied in rats with streptozocin-induced diabetes. Half of the rats were given AG (100 mg/kg/day) while the remainder received no treatment. Vitreous fluorophotometry was performed on all rats before STZ injection and 2 weeks after induction of diabetes mellitus. Two weeks(More)
Dendritic cell (DC) immunotherapy is a strong candidate for the treatment of incurable cancers especially malignant melanoma. Nevertheless, the proper guideline of DC immunotherapy does not exist. The absence of the guideline is also an obstacle to clinical trials of DC immunotherapy. So we conducted this study in order to develop an effective DC(More)
A low-resistance ohmic contact to Mg-doped p-type GaN grown by metal-organic chemical vapor deposition (MOCVD) with a carrier concentration of 2 · 10 cm 3 using Pd/Ni/Au metallization was formed. An anneal at 500 C for 1 min in a flowing N2 ambient produced an excellent ohmic contact with a specific contact resistivity as low as 2.4 · 10 5 X cm. X-ray(More)
We propose and demonstrate evanescently-decoupled, solid-angle-optimized distributed Bragg reflectors (DBRs) for AlGaInP light-emitting diodes (LEDs). The thickness of each DBR layer is tuned to the wavelength slightly longer than the emission peak of the active medium in order to maximize the radiated power integrated over the top surface. In addition, to(More)
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