熱製程對氮化銦鎵薄膜及量子井發光二極體光學特性之研究

Abstract

本論文主要研究熱製程對氮化銦鎵磊晶薄膜，氮化銦鎵/氮化鎵發光二極體光學特性之影響。實驗中發現快速退火處理會使X光繞射及光激螢光光譜的半高寬變小，這是因為熱處理步驟使得材料磊晶品質提高所致。在熱製程對氮化銦鎵磊晶薄膜研究中，發現隨著不同退火溫度，光激螢光光譜會有紅移及藍移的現象，這是因為氮化銦鎵磊晶薄膜中銦的含量隨熱製程之溫度變化而產生變化。在熱製程對氮化銦鎵/氮化鎵發光二極體光學特性研究中，發現隨著不同退火溫度，光激螢光光譜會有藍移及紅移的現象，這是因為發光二極體中的氮化銦鎵/氮化鎵量子井中的位能受到改變而產生位移。此外氮化鎵發光二極體發光強度隨溫度升高而變強，700℃熱退火最強。因此適當的熱退火會改善氮化銦鎵磊晶薄膜及氮化銦鎵/氮化鎵發光二極體的材料品質及光學特性。

In this thesis, thermal effect on the optical properties of InGaN epilayer and InGaN LED was investigated. In the section of thermal effect on the optical property of InGaN epilayer, the value of full-width at half-maximum (FWHM) of X-ray diffraction and photoluminescence (PL) spectrum were reduced after thermal annealing process. This is because of the crystal quality was improved by thermal annealing treatment. The red and blue shift of PL spectrum was observed in the different thermal annealing temperature. This is due to the In contain was changed in the InGaN epilayer after different thermal annealing temperature. In the section of thermal effect on the optical property of InGaN LED, the blue and red shift of PL spectrum was observed in the different thermal annealing temperature is due to the change of the potential energy of the quantum wells in LED structures. Beside, the intensity of the PL spectrum was increase with increasing the annealing temperature. The highest intensity was observed in the 700℃ annealed sample. Therefore, the optical properties of InGaN epilayer and InGaN LED can be improved by suitable annealing temperature.