電機資訊學院: 電子工程學研究所指導教授: 管傑雄陳彥蒲Chen, Yen-PuYen-PuChen2017-03-062018-07-102017-03-062018-07-102015http://ntur.lib.ntu.edu.tw//handle/246246/276424在發光二極體(Light-Emitting Diodes, LEDs)中使用圖案化藍寶石基板(Patterned Sapphire Substrates, PSSs)可以減少穿隧差排密度(Threading Dislocation Density)以增加磊晶品質，以及增加光萃取率(Light Extraction Efficiency, LEE)。和業界量產型圖案化藍寶石基板主要追求光萃取率不同，我們製作的基板上微結構的高度只有其三分之一，但是我們發現隨著改變微結構不同的頂部c-plane大小和不同濕蝕刻所形成的微結構深度，成長於其上的氮化鎵晶體將受到不同的應力，且此應力會影響到發光二極體結構中的多重量子井(Multiple Quantum Wells, MQWs)中的量子侷限史塔克效應(Quantum-Confined Stark Effect, QCSE)，藉此增加載子複合效率。 在最後封裝完成的階段，論文會探討如何經由調變其微結構之幾何形狀來達到減少量子侷限史塔克效應，以及驗證效率衰退(Efficiency Droop)和量子侷限史塔克效應的關係。最後，在同樣長晶參數下，和成長於乾蝕刻之量產型圖案化藍寶石基板的元件(Conventional PSSs, CPSSs)亮度作比較，可以達到其95%的輸出瓦數，表示減低量子侷限史塔克效應很有效的提升了元件的性能。GaN-based light-emitting diodes (LEDs) are typically grown on c-plane sapphire, or even patterned sapphire substrates (PSSs). In the same growth condition, we adopt wet etching to fabricate our PSSs with structure depth about 0.5µm instead of dry etching with depth up to 1.6µm. However, we find that the quantum-confined Stark effect (QCSE) can be reduced by changing the geometry of PSSs. Moreover, we have found a probable key parameter which dominates the QCSE magnitude, so that we can predict a probable range to further minimize the QCSE. In the device level, we demonstrate that by reducing QCSE, the optical performance of LED devices such as internal quantum efficiency (IQE) and external quantum efficiency (EQE) can be enhanced, but efficiency droop is larger. After our analysis through the differential of EQE, the efficiency droop should be attributed to the consequence of increasing IQE. In the end, in comparison to the LED devices grown on conventional PSSs, our light output power (LOP) and EQE can reach up to 95% of the conventional one. Therefore, the reduction of QCSE is effective to enhance the performance of LEDs, and it’s potential to be an alternative to fabricate LEDs without changing the crystal growth conditions.4533078 bytesapplication/pdf論文公開時間: 2018/7/29論文使用權限: 同意有償授權(權利金給回饋學校)發光二極體氮化鎵圖案化藍寶石基板濕式蝕刻電子束微影量子侷限史塔克效應Light-Emitting DiodeGaNPatterned Sapphire SubstrateWet-EtchingElectron-Beam LithographyQuantum-Confined Stark Effectthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/276424/1/ntu-104-R02943053-1.pdf