Journal of South China University of Technology (Natural Science Edition) ›› 2014, Vol. 42 ›› Issue (8): 14-20.doi: 10.3969/j.issn.1000-565X.2014.08.003

• Physics • Previous Articles     Next Articles

GaN-Based Light-Emitting Diode Chip with Patterned Al Backside Reflector

Huang Hua-mao Hu Jin-yong Wang Hong   

  1. School of Physics and Optoelectronics,South China University of Technology / /Engineering Research Center forOptoelectronics of Guangdong Province,Guangzhou 510640,Guangdong
  • Received:2014-02-27 Revised:2014-05-09 Online:2014-08-25 Published:2014-07-01
  • Contact: 王洪(1964-),男,博士,教授,主要从事微纳光电子材料与器件、光通信网络研究. E-mail:phhwang@scut.edu.cn
  • About author:黄华茂(1982-),男,博士,助理研究员,主要从事微纳光电子集成、LED 外延芯片设计与制备研究. E-mail:schhm@scut.edu.cn
  • Supported by:

    国家“863”计划项目( 2014AA032609) ; 广东省战略性新兴产业发展专项资金资助项目( 2010A081002009,2011A081301004, 2012A080302003) ; 华南理工大学中央高校基本科研业务费专项资金资助项目( 2013ZM093, 2013ZP0017)

Abstract:

Patterned reflectors can improve the light-extraction efficiency of light-emitting diode ( LED) chips.Inthe investigation,a triangular lattice of the micro-scale SiO2-cone array was placed on the backside of a sapphiresubstrate,and then the metal Al was deposited on the lattice,so that a patterned reflector was built.Three-dimensionalsimulation results obtained through the Monte Carlo ray tracing method show that,as compared with the planemirror,the SiO2-cone patterned Al backside reflector can improve the light-extraction efficiency of LED chips by7.5%.Experimental results indicate that,when the injection current is 20mA,the LED samples with the patternedreflector achieve a light-output power increase by 8.4% without the degradation of the electrical performance,incomparison with those with plane mirrors.It is found from the two-dimensional finite-element thermodynamic simulationsthat the pattern reflector helps to achieve lower chip temperature and smaller chip thermal-stress in comparisonwith the plane mirror.In addition,the thermal stress concentration in the vicinity of micro-structures has littleeffect on the performance of LED chips.

Key words: patterned backside reflector, light-emitting diode chip, light-output efficiency, thermal stress

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