GaN-based flip-chip LEDs with highly reflective ITO/DBR p-type and via hole-based n-type contacts for enhanced current spreading and light extraction

被引：41
作者：
Zhou, Shengjun [1 ,3 ]
Zheng, Chenju [1 ]
Lv, Jiajiang [1 ]
Gao, Yilin [1 ]
Wang, Ruiqing [2 ]
Liu, Sheng [1 ]
机构：
[1] Wuhan Univ, Sch Power & Mech Engn, Wuhan 430072, Peoples R China
[2] Shenzhen Top Chip Technol Co LTD, Shenzhen 518000, Peoples R China
[3] Shanghai Jiao Tong Univ, Sch Mech Engn, Shanghai 200240, Peoples R China
来源：
OPTICS AND LASER TECHNOLOGY | 2017年 / 92卷
基金：
中国国家自然科学基金;
关键词：
EMITTING-DIODES; OHMIC CONTACTS; EFFICIENCY;
D O I：
10.1016/j.optlastec.2017.01.017
中图分类号：
O43 [光学];
学科分类号：
070207 ; 0803 ;
摘要：
We demonstrate GaN-based double-layer electrode flip-chip light-emitting diodes (DLE-FCLED) with highly reflective indium-tin oxide (ITO)/distributed bragg reflector (DBR) p-type contact and via hole-based n-type contacts. Transparent thin ITO in combination with TiO2/SiO2 DBR is used for reflective p-type ohmic contact, resulting in a significant reduction in absorption of light by opaque metal electrodes. The finely distributed via hole-based n-type contacts are formed on the n-GaN layer by etching via holes throUgh p-GaN and multiple quantum well (MQW) active layer, leading to reduced lateral current spreading length, and hence alleviated current crowding effect. The forward voltage of the DLE-FCLED is 0.31 V lower than that of the top-emitting LED at 90 mA. The light output power of DLE-FCLED is 15.7% and 80.8% higher than that of top-einitting LED at 90 mA and 300 mA, respectively. Compared to top- emitting LED, the external quantum efficiency (EQE) of DLE-FCLED is enhanced by 15.4% and 132% at 90 mA and 300 mA, respectively. The maximum light output power of the DLE-FCLED obtained at 195.6 A/cm(2) is 1.33 times larger than that of the top-emitting LED obtained at 93 A/cm(2).
引用
收藏
页码：95 / 100
页数：6
相关论文
共 32 条
  • [1] Light emitting diodes reliability review[J]. Chang, Moon-Hwan;Das, Diganta;Varde, P. V.;Pecht, Michael. MICROELECTRONICS RELIABILITY, 2012(05)
  • [2] Nitride-based flip-chip LEDs with transparent ohmic contacts and reflective mirrors[J]. Chang, S. J.;Chen, W. S.;Lin, Y. C.;Chang, C. S.;Ko, T. K.;Hsu, Y. P.;Shen, C. F.;Tsai, J. M.;Shei, S. C. IEEE TRANSACTIONS ON ADVANCED PACKAGING, 2006(03)
  • [3] Reduction of Thermal Resistance and Optical Power Loss Using Thin-Film Light-Emitting Diode (LED) Structure[J]. Chen, Huan Ting;Cheung, Yuk Fai;Choi, Hoi Wai;Tan, Siew Chong;Hui, S. Y. IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, 2015(11)
  • [4] Study of light extraction efficiency of flip-chip GaN-based LEDs with different periodic arrays[J]. Chen, Xinlian;Kong, Fanmin;Li, Kang;Ding, Qingan;Zhang, Mingyu;Li, Wei. OPTICS COMMUNICATIONS, 2014
  • [5] Novel thin-GaN LED structure adopted micro abraded surface to compare with conventional vertical LEDs in ultraviolet light[J]. Chiang, Yen Chih;Lin, Chien Chung;Kuo, Hao Chung. NANOSCALE RESEARCH LETTERS, 2015
  • [6] Performance Enhancements of Flip-Chip Light-Emitting Diodes With High-Density n-Type Point-Contacts[J]. Chong, Wing Cheung;Lau, Kei May. IEEE ELECTRON DEVICE LETTERS, 2014(10)
  • [7] Improving the Vertical Light Extraction Efficiency of GaN-Based Thin-Film Flip-Chip LED With Double Embedded Photonic Crystals[J]. Ding, Qing-An;Li, Kang;Kong, Fanmin;Zhao, Jia;Yue, Qingyang. IEEE JOURNAL OF QUANTUM ELECTRONICS, 2015(02)
  • [8] Current crowding and optical saturation effects in GaInN/GaN light-emitting diodes grown on insulating substrates[J]. Guo, X;Schubert, EF. APPLIED PHYSICS LETTERS, 2001(21)
  • [9] High performance GaN-based flip-chip LEDs with different electrode patterns[J]. Horng, Ray-Hua;Chuang, Shih-Hao;Tien, Ching-Ho;Lin, Sin-Cyuan;Wuu, Dong-Sing. OPTICS EXPRESS, 2014(09)
  • [10] Effects of pre-annealed ITO film on the electrical characteristics of high-reflectance Ni/Ag/Ni/Au contacts to p-type GaN[J]. Hu, Xiao-Long;Liu, Li;Wang, Hong;Zhang, Xi-Chun. APPLIED SURFACE SCIENCE, 2015
1234