為更進一步提升垂直結構氮化鎵系列發光二極體(LED)之發光效率，採用聚苯乙烯小球(Polystyrene spheres, PSs)鋪排於元件表面當作奈米等級的蝕刻光罩，再透過乾蝕刻的方式將圖樣轉移至n-GaN表面達到粗化的目的。實驗結果顯示，利用此一技術LED之光輸出功率(Light output power, LOP)於電流350 mA下可獲得36.82%之提升。
此外，本研究亦提出製作圖樣式銦鋅氧化物(patterned IZO)透明導電層之垂直結構LED。在先前實驗室已成功研製出具IZO透明導電層之高功率大面積垂直結構GaN-based LED，在光電特性上都有一定程度的改善，為了更進一步提升發光效率，製作出具有Patterned IZO透明導電層之垂直結構LED，同樣利用PSs當作奈米遮罩，沉積出凹凸狀的 IZO薄膜，由於凹凸狀的薄膜，使得光受到元件內部全反射機會減少，而與整面IZO透明導電層之垂直結構LED相比，光輸出功率增加19.4%。

Devices with a vertical structure would allow a much large power handling capability due to the immune of current crowding effect. In this study, Vertical-conducting Metal-substrate GaN-based Light-Emitting Diodes (VM-LEDs) were fabricated by using of nickel electroplating substrate transformation in conjunction with laser lift-off (LLO) technique. To further improve light output power of VM-LEDs, a cost-effective and efficient surface roughening technology using polystyrene spheres (PSs) as an etching mask was proposed and demonstrated. Experimental results revealed that the proposed structure could effectively enhance extraction for VM-LEDs. As compare to VM-LEDs of the same size (1000×1000 µm2), electrical characteristics of the fabricated devices are similar, but with an enhancement in light output power by 36.82% at 350 mA.
To further improve light output power of LEDs, an IZO layer with a patterned surface was also formed atop the LEDs by using the proposed PSs nano-mask process. As compare to VM-LEDs with IZO TCL but without PS patterning, typical improvement in light output power under an injection current of 350 mA by about 19.4% has been obtained.

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