新型電子阻擋層以提升氮化鎵發光二極體的發光效率

Efficiency Improvement in GaN-based Light-emitting Diodes by Novel Electron Blocking Layer

王朝勳(Chao-Hsun Wang) ； 張世邦(Shih-Pang Chang) ； 張瑋婷(Wei-Ting Chang) ； 李金釵(Jin-Chai Li) ； 郭浩中(Hao-Chung Kuo) ； 盧廷昌(Tien-Chang Lu)

《真空科技》 24卷3期 (2011/09) Pp. 60-64

https://doi.org/10.29808/JVSROC.201109.0009

摘要

利用能帶工程的方法設計出具有漸變鋁成分的電子阻擋層（GEBL）的氮化鎵發光二極體（Light-emitting Diodes, LEDs），其中電子阻擋層鋁的成分沿著[0001]方向增加。由模擬結果可以看到GEBL大幅改善電洞在電子阻擋層的傳輸效果，同時也增強了電子阻擋層侷限電子的能力。接著我們利用金屬有機化學氣相沉積（Metal-organic Chemical Vapor Deposition, MOCVD）成長出的GEBL發光二極體相對於傳統發光二極體，擁有較小的操作電壓與串聯電阻值，並且在高電流密度下擁有較高的輸出功率。同時在電流密度為200A／cm^2下，效率隨電流增大而降低的效應也達到大幅的改善，傳統發光二極體效率遞減34％而GEBL發光二極體只有4％。

關鍵字

氮化鎵發光二極體 ； 能帶工程 ； 電子阻擋層 ； 效率下降

並列摘要

A graded-composition electron blocking layer (GEBL) with aluminum composition increasing along [0001] direction was designed for GaN-based light-emitting diodes (LEDs) by employing the band engineering. The simulation results demonstrated that such GEBL can effectively enhance the capability of hole transportation across the EBL as well as the electron confinement. Consequently, the LED with GEBL grown by metal-organic chemical vapor deposition exhibited lower forward voltage and series resistance, and much higher output power at high current density, as compared to conventional LED. Meanwhile, the efficiency droop was reduced from 34% in conventional LED to only 4% from the maximum value at low injection current to 200 A/cm^2.

並列關鍵字

GaN-based LEDs ； Band Engineering ； Electron Blocking Layer ； Efficiency Droop