High power InGaN/GaN flip-chip LEDs with via-hole-based two-level metallization electrodes

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• 作者：Jiajiang Lv ; Chenju Zheng ; Quan Chen ; Shengjun Zhou and Sheng Liu
• 刊名：physica status solidi (a)
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：213
• 期：12
• 页码：3150-3156
• 全文大小：1185K
• ISSN：1862-6319

文摘

High power flip-chip light-emitting diodes with distributed n-type via-hole-based two-level metallization electrodes (TLM-FCLED) were fabricated and investigated. Comparison tests altering Ni metal thickness and annealing temperature were performed to optimize the reflectivity of Ni/Ag reflective layer, which enhanced the light extraction efficiency. On the other hand, via-hole-based n-contact electrodes structure increased the utilization ratio of active region area, and the introduction of first metallization layer allowed n-contact to be arranged uniformly on the entire n-GaN surface, which exhibited a more favorable current spreading uniformity. As a result, the light output power (LOP) of TLM-FCLED was 9.23 and 26.55% higher than that of conventional high power LED (CHP-LED) at 350 and 1050 mA. The CHP-LED exhibited 13.39% external quantum efficiency (EQE) degradation from 350 to 1050 mA, whereas the TLM-FCLED exhibited only 6.88% EQE degradation. It is noted that the maximum LOP was about 1264 mW at 1830 mA, thereby, suggesting the potential of its application in ultra-high power applications.