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

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

Analysis of Electrical/optical Characteristics Using Asymmetric MQW Structures for Deep-UV LEDs

비대칭 MQW 구조를 이용한 Deep-UV LED의 전기적/광학적 특성

  • Son, Sung-Hun (School of Electrical Engineering, Korea University) ;
  • Kim, Su-Jin (School of Electrical Engineering, Korea University) ;
  • Kim, Tae-Geun (School of Electrical Engineering, Korea University)
  • 손성훈 (고려대학교 전자전기공학과) ;
  • 김수진 (고려대학교 전자전기공학과) ;
  • 김태근 (고려대학교 전자전기공학과)
  • Received : 2011.11.03
  • Accepted : 2012.05.17
  • Published : 2012.05.25
Download PDF
⟨ Previous Next ⟩

Abstract

In this work, we proposed the asymmetric MQW structure with gradually increased or decreased well thickness from n-layers to p-layers in order to improve the performance of DUV-LEDs. We report the simulation results of electrical/optical characteristics by using the SimuLED program. From the simulation results, we found that B structure with thickness of the wells gradually increased from the n-side to the p-side has the same forward voltage(Vf) as standard structure, but the light output power (Pout) was improved by a factor of 1.17 at 20mA compared with those of the standard structure.

본 논문에서는 고효율 고출력 DUV(Deep Ultra Violet)-LED(Light Emitting Diodes)의 구현을 위하여 n-side에서 p-side로 well 두께를 다르게 형성하는 비대칭 MQW 에피구조를 제안하였다. 제안된 구조의 물리적 해석을 위해 상용화된 3차원 시뮬레이터 SimuLEDTM을 이용하여 소자의 전기적/광학적 특성을 비교 분석 하였다. 시뮬레이션 결과, 본 연구에서 제안한 B구조(n-side에서 p-side 방향으로 well 두께를 2 nm, 3 nm, 4 nm 로 제작)의 에피층을 가지는 UV-LED는 기본 MQW 에피구조를 가지는 UV-LED와 동작전압은 8.9 V로 동일한 값을 가졌지만 광출력은 기본구조의 10.6 mW 에 비해 약 1.17배 향상된 12.4 mW의 값을 가지는 것을 확인하였다.

Keywords

References

  1. H. Hirayama, Y. Tsukada, T. Maeda, and N. Kamata, "Marked Enhancement in the Efficiency of Deep-Ultraviolet AlGaN Light-Emitting Diodes by Using a Multiquantum-Barrier Electron Blocking Layer," Applied Physics Express Vol. 3, No. 3, pp. 031002-1, 2010. https://doi.org/10.1143/APEX.3.031002
  2. K. Mayes, A. Yasan, R. McClintock, D. Shiell, S. R. Darvish, P. Kung, and M. Razeghi, "High-power 280 nm AlGaN light-emitting diodes based on an asymmetric single-quantum well," Appl. Phys. Lett. Vol. 84, No. 7, pp. 1046-1048, 2004. https://doi.org/10.1063/1.1647273
  3. Miao-Chan Tsai, Sheng-Horng Yen, and Yen-Kuang Kuo, "Deep-ultraviolet light-emitting diodes with gradually increased barrier thicknesses from n-layers to p-layers," Appl. Phys. Lett. Vol. 98, No. 11, p. 111114-1, 2011.
  4. Jianchang Yan, Junxi Wang, Peipei Cong, Lili Sun, Naixin Liu, Zhe Liu, Chao Zhao, and Jinmin Li, "Improved performance of UV-LED by p-AlGaN with graded composition," Phys. Status Solidi C. Vol. 8, No. 2, pp. 461-463, (2011). https://doi.org/10.1002/pssc.201000458
  5. C. H. Wang, S. P. Chang, W. T. Chang, J. C. Li, Y. S. Lu, Z. Y. Li, H. C. Yang, H. C. Kuo, T. C. Lu, and S. C. Wang, "Efficiency droop alleviation in InGaN/GaN light-emitting diodes by graded-thickness multiple quantum wells," Appl. Phys. Lett. Vol. 97, No. 18, p. 181101-1, 2010. https://doi.org/10.1063/1.3507891
  6. Man-Fang Huang, and Tsung-Hung Lu, "Optimization of the Active-Layer Structure for the Deep-UV AlGaN Light-Emitting Diodes," IEEE J. Quantum Electron., Vol. 42, No. 8, pp. 820-826, 2006. https://doi.org/10.1109/JQE.2006.877217
  7. Yen-Kuang Kuo, Sheng-Horng Yen, and Yu-Wen Wang, "Simulation of deep ultraviolet light-emitting diodes," SPIE, Vol. 6669, p. 66691J-1, 2007.
  8. Man-Fang Huang, and Tsung-Hung Lu, "Improvement of ultra-deep ultraviolet light emitting diodes with asymmetric active region," SPIE, Vol. 6134, p. 61340O-1, 2006.