Main > Photonics Research >  Volume 7 >  Issue 9 >  Page B66-B72 > Article
Photonics Research, Vol. 7, Issue 9, B66-B72 (2019)

Deep ultraviolet light-emitting diodes based on well-ordered AlGaN nanorod array

Liang Zhang1,2, Yanan Guo1,2,3,4, Jianchang Yan1,2,3,4,6,*, Qingqing Wu1,2, Yi Lu1,2, Zhuohui Wu1,2, Wen Gu1,2, Xuecheng Wei1,2,3,4, Junxi Wang1,2,3,4,5,*, and Jinmin Li1,2,3,4

Author Affiliations

  • 1Research and Development Center for Solid State Lighting, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
  • 2Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
  • 3Beijing Engineering Research Center for the 3rd Generation Semiconductor Materials and Application, Beijing 100083, China
  • 4State Key Laboratory of Solid-State Lighting, Beijing 100083, China
  • 5e-mail: jxwang@semi.ac.cn
  • 6e-mail: yanjc@semi.ac.cn

Abstract

The nanorod structure is an alternative scheme to develop high-efficiency deep ultraviolet light-emitting diodes (DUV LEDs). In this paper, we first report the electrically injected 274-nm AlGaN nanorod array DUV LEDs fabricated by the nanosphere lithography and dry-etching technique. Nanorod DUV LED devices with good electrical properties are successfully realized. Compared to planar DUV LEDs, nanorod DUV LEDs present >2.5 times improvement in light output power and external quantum efficiency. The internal quantum efficiency of nanorod LEDs increases by 1.2 times due to the transformation of carriers from the exciton to the free electron–hole, possibly driven by the interface state effect of the nanorod sidewall surface. In addition, the nanorod array significantly facilitates photons escaping from the interior of LEDs along the vertical direction, contributing to improving light extraction efficiency. The three-dimensional finite-different time-domain simulation is performed to further analyze in detail the TE- and TM-polarized photons extraction mechanisms of the nanostructure. Our results demonstrate the nanorod structure is a good candidate for high-efficiency DUV emitters.