대한전자공학회논문지SD (Journal of the Institute of Electronics Engineers of Korea SD)

대한전자공학회 (The Institute of Electronics and Information Engineers)
권호 표지

마그네슘이 도핑된 GaN 공간층과 양자장벽층을 이용한 무분극 GaN 발광다이오드의 전기적/광학적 특성 향상

Improvement of Electrical/optical Characteristics Using Mg-doped GaN Spacers and Quantum Barriers for Nonpolar GaN light-emitting Diodes

  • 김동호 (고려대학교 전자전기공학과) ;
  • 손성훈 (고려대학교 전자전기공학과) ;
  • 김태근 (고려대학교 전자전기공학과)
  • Kim, Dong-Ho (School of Electronics and Electrical Engineering, Korea University) ;
  • Son, Sung-Hun (School of Electronics and Electrical Engineering, Korea University) ;
  • Kim, Tae-Geun (School of Electronics and Electrical Engineering, Korea University)
  • 투고 : 2011.01.18
  • 심사 : 2011.07.06
  • 발행 : 2011.07.25
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초록

본 논문에서는 고효율 고출력 무분극 GaN LED의 구현을 위하여 Mg이 도핑된 GaN spacer층 및 GaN quantum barrier(QB)층을 삽입한 구조를 제안하였다. 제안한 구조에 대한 물리적 해석을 위하여 일반적인 무분극 LED 에피구조와 본 연구에서 제안한 p-GaN spacer층 및 p-GaN QB층이 삽입된 무분극 LED 에피구조에 대해 상용화된 $SimuLED^{TM}$ 시뮬레이터를 이용하여 전기적/광학적 특성을 비교 분석하였다. 실험 결과, 본 연구에서 제안한 무분극 LED는 20 mA의 전류주입 하에서 동작전압($V_f$)이 일반적인 무분극 LED에 비해 약 3.7% 감소된 3.67 V의 전기적 특성을 갖는 것을 확인하였고, 광출력은 약 7% 향상된 2.13 mW의 광학적 특성을 갖는 구조임을 확인하였다. 또한, 내부양자효율(Internal quantum efficiency, IQE)과 광방출세기(emission peak intensity) 역시 각각 9.1% 및 170% 향상된 우수한 특성을 갖는 에피구조임을 확인하였다.

We report on the simulation results of electrical/optical characteristics for nonpolar GaN LED having Mg-doped GaN spacer and quantum barrier, in comparison with those of the typical nonpolar GaN LED. In order to reduce the band-gap energy distortion and conduction-band discontinuity in InGaN/GaN multiple quantum wells(MQWs) of nonpolar GaN LED, and thereby to increase their current-voltage, light output power and emission peak intensity, we applied 6 nm-thick p-type($1{\times}10^{18}\;cm^{-3}$) GaN spacer and GaN QB schemes to the typical nonpolar GaN LED epitaxial structure. As a result, we found that the radiative recombination rate was increased by 23% in MQWs at 20 mA current injection. Also, the forward voltage($V_f$) and the light output power($P_{out}$) were improved by 3.7% and 7%, respectively, for the proposed nonpolar LED epitaxial structure, compared with those of the typical nonpolar GaN LED.

키워드

참고문헌

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