楊志忠臺灣大學：光電工程學研究所林仕駿Lin, Shih-ChunShih-ChunLin2007-11-252018-07-052007-11-252018-07-052004http://ntur.lib.ntu.edu.tw//handle/246246/50645在本研究中，我們探討了五個氮化銦鎵/氮化鎵多重量子井結構及其熱退火效應的光學特性結果。首先，我們針對五個銦含量相同但量子井寬度不同的樣品做了有系統性的分析。樣品在不同溫度區間顯示出不同的頻譜峰值能量及內部量子效率。從時間解析螢光光譜的實驗結果，我們發現螢光光譜的衰減時間會隨著量子井厚度增加而變長。這個趨勢是由於增加量子井厚度會有較強的載子侷限及較大的壓電場所造成。然後，我們將不同量子井寬度的樣品做800 ℃，為時10分鐘不同降溫速率的熱退火處理。根據螢光光譜、螢光激發光譜與時間解析螢光光譜的實驗結果，我們發現經過慢速降溫之熱退火處理後，使得頻譜峰值能量發生藍移，同時也提高了它的發光效率並增長了螢光光譜的衰減時間。然而快速降溫的樣品頻譜峰值能量發生紅移，並降低了發光效率。由根據穿透式電子顯微術所得到的應變分析結果顯示相同的趨勢，不同熱退火處理條件會對量子點奈米結構及量子井界面特性造成影響。In this research, optical characterization results of five InGaN/GaN multiple quantum well structures and their thermal annealing effects are reported. First, we present systematical results of the as-grown samples of the same indium content but different quantum well widths. The photoluminescence (PL) peak positions and internal quantum efficiencies of the samples show different behaviors between three temperature ranges. From time-resolved PL (TRPL) measurements, we can see that PL decay times become longer with increasing well width. This trend can be attributed to stronger carrier localizations and larger piezoelectric fields in increasing well width. Then, we conduct post-growth thermal annealing on our samples of different well widths at 800 ℃ for 10 min with different cooling rates. Base on the results of PL, photoluminescence excitation (PLE) and TRPL measurements, thermal annealing with the slow cooling rate leads to the blue shift of PL peak, higher radiative efficiency, and longer PL decay time. However, in the samples with the fast cooling rate, we observe the red shift of PL peak and radiative efficiency degradation. The strain-state analysis results, based on transmission electron microscopy, show the consistent trends. The quantum-dot like nano-structures and the interfaces of quantum wells change with different thermal annealing conditions.Chapter 1 Introduction…………………………………………1 1.1 Applications of Nitride-Based Materials……………………………1 1.2 Review on the characteristics of InGaN/GaN Structure…………….2 1.2.1Indium Aggregation and Quantum-dot Like Structures………..2 1.2.2Strain and Strain-induced Piezoelectric Field………………….4 1.2.3Spinodal Decomposition……………………………………….6 1.2.4Thermal Properties……………………………………………..8 1.2.5Band-tail Model and Temperature Dependence of Band Gap…9 1.3 Post-growth Thermal Annealing…………………………………...11 1.4 Influence of Quantum Well Thickness on Radiative Recombination in InGaN/GaN Quantum Well Structures………………………….12 1.5 Research Motivations and Thesis Organization…………………...15 Chapter 2 Experimental Procedures and Basic Properties of Samples…………………………………………26 2.1 Sample Structures…………………………………………………26 2.2 Optical Analysis Methods………………………………………....26 2.2.1 Photoluminescence (PL) Measurements……………………..26 2.2.2 Photoluminescence Excitation (PLE) Measurements………..27 2.2.3 Time-resolved Photoluminescence (TRPL) Measurements….28 2.3 Optical Measurement Results……………………………………...29 2.3.1 PL Measurement Results……………………………………..29 2.3.2 TRPL Measurement Results………………………………….31 2.4 Strain-state Analysis(SSA) Results ……………………………….33 2.5 Summary…………………………………………………………..36 Chapter 3 Effects of Thermal Annealing……………………..63 3.1 Post-grown Thermal Annealing……………………………………63 3.2 PL Results………………………………………………………….63 3.3 PLE Results……………………………………………………….65 3.4 TRPL Results……………………………………………………..66 3.5 SSA Results……………………………………………………….67 3.6 Summary………………………………………………………….69 Chapter 4 Conclusions……………………………………..102 References………………………………………………….1043822393 bytesapplication/pdfen-US氮化銦鎵量子井氮化鎵GaNQWInGaNthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/50645/1/ntu-93-R91941033-1.pdf