Study on GaN Light Emitting Diodes with Imbeded Electrodes

• Main Authors: Yi-An Lu, 盧怡安
• Other Authors: Ray-Hua Horng
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/27893743342506275485

碩士 === 國立中興大學 === 精密工程學系所 === 98 === Textured n-GaN side up LED with interdigitated imbedded electrodes (IIE) eliminating the electrode-shading loss with high reflection mirror on silicon substrate and double-side roughening both p-GaN and undoped-GaN layers have been investigated. The devices are subsequently fabricated with wafer-bond, laser lift-off and chemical dry/wet etching techniques. The roughness on p-GaN surface was fabricated via low temperature growth, and that on n-GaN surface was made by wet-etching. This n-GaN side up structure was useful to avoid light-absorbing and enhance the light efficiency. We compared the performance of 4-types LEDs: Original-LED/Sapphire with single rough surface(SR-LED), p-side up-LED with double rough surface(DR-LED), n-side up-DR-LED, n-side up-DR-VB(vertical electrodes by wafer bonding)LED. The forward voltage(at 350 mA) of 4-types LEDs is 4.06 V, 4.11 V, 4.38 V, 4.97 V respectively. The luminance intensity of the final 3-types LEDs(at 700 mA) is 119.83 %, 158.74 % and 26.64 % higher than that of the original LED, respectively. The performance of p-side up-DR-LED which is 119.83 % higher than that of original structure, yet worse than n-side up-DR-LED. It was worthy to mention that the area of electrode shading is only 13% of the light emitting area. Therefore, the obtained above results suggest that the optimum thin film LED structure is the n-GaN with double surface roughness and the high reflection mirror.