아래와 같이 콜로퀴움을 개최하오니 많이 참석해 주시기 바랍니다. 아 래 1. 제목: 백색 LED를 이용한 반도체조명에 관하여 2. 연사: 서 은 경 교수 (전북대학교) 3. 일시: 2006년 6월 2일(금요일) 오후 5시 00분 4. 장소: 물리학과 세미나실(31355호실) 5. 초록: GaN and its ternary alloys have attracted much attention for optoelectronic device applications whose emission wavelengths ranging from visible to uv light. Applicaitons of LEDs are widely expanded into the out-door display, LCD back light unit, traffic signal, and automotive illuminations. It is expected that LEDs will replace the present incandescent light bulb, for example, the combiantion of near UV or blue LEDs with optimized phosphors enabled the fabrication of highly efficient solid state light sources for illumination. However, many challenges remain for high power III-N based LEDs both in basic materials and device performance to meet the demands of increasing applications. For example, high efficiency green LEDs are one of the key elements in realizing high brightness RGB based white lighting systems. But, LEDs emitting at green wavelengths have suffered from a low internal quantum efficiency compared to blue and red, which is believed to be related to epitaxial materials quality and the fundamental structure of green LEDs. Also, InGaN based LEDs tend to exhibit reduced efficiency when the current density increses, possibly due to insufficient carrier confinement at high injection currents. Several challenges and current research topics will be discussed.