Improved performance of 375 nm InGaN/AlGaN light-emitting diodes by incorporating a heavily Si-doped transition layer Shih-Cheng Huang, a, e Kun-Ching Shen, a Po-Min Tu, b Dong-Sing Wuu,* , a, d Hao-Chung Kuo, b and Ray-Hua Horng c a Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan, ROC b Department of Photonics and Institute of Electro-Optical Engineering, National Chiao-Tung University, Hsinchu 30010, Taiwan, ROC c Department of Electro-Optical Engineering, National Cheng Kung University, Tainan 70101, Taiwan, ROC d Department of Materials Science and Engineering, Da-Yeh University, Changhua 51591, Taiwan, ROC e Advanced Optoelectronic Technology Inc., Hsinchu 30352, Taiwan, ROC ABSTRACT High performance 375-nm ultraviolet (UV) InGaN/AlGaN light-emitting diodes (LEDs) was developed using a heavy Si-doping technique with metalorganic chemical vapor deposition (MOCVD). From the transmission electron microcopy (TEM) image, the dislocation density was reduced after inserting a heavily Si-doping growth mode transition layer (GMTL) between un-doped GaN layer and Si-doped Al 0.02 Ga 0.98 N contact layer. The internal quantum efficiency (IQE) of the sample with GMTL measured by power-dependent photoluminescence shows 39.4% improved compared with the sample without GMTL. When the vertical type LED chips (size: 1mm×1mm) driving by a 350-mA current, the output powers of the LEDs with and without GMTL were measured to be 286.7 mW and 204.2 mW, respectively. As much as 40.4% increased light output power was achieved. Therefore, using the GMTL to reduce dislocation defects would be a promising prospective for InGaN/AlGaN UV LEDs to achieve high internal quantum efficiency. Keywords: Light emitting diodes, Si-doping *dsw@dragon.nchu.edu.tw; phone: 886-4-22840500 ext. 714; fax: 886-4-22855046 Gallium Nitride Materials and Devices VII, edited by Jen-Inn Chyi, Yasushi Nanishi, Hadis Morkoç, Joachim Piprek, Euijoon Yoon, Proc. of SPIE Vol. 8262, 82621L © 2012 SPIE · CCC code: 0277-786X/12/$18 · doi: 10.1117/12.909580 Proc. of SPIE Vol. 8262 82621L-1 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/20/2013 Terms of Use: http://spiedl.org/terms