陳永芳臺灣大學：物理研究所陳奕任Chen, I-JenI-JenChen2007-11-262018-06-282007-11-262018-06-282007http://ntur.lib.ntu.edu.tw//handle/246246/54522在這一篇論文之中，我們利用雙光源激發的螢光光譜法來研究氮化銦鎵/氮化鎵多重量子井結構中的非輻射缺陷。我們可以發現當多增加一道能量較樣品能隙小的激發光源時，樣品的螢光光譜強度會減弱百分之五十以上，同時，載子的生命週期也會由173.9奈秒減少到7.9奈秒，而減少的程度則由這道激發光強度而定，我們可以利用載子在砷化鎵缺陷能階之間的傳輸模型來解釋這個實驗結果。另外在實驗中，藉由改變這道能量較樣品能隙小的激發光源的能量，我們就可以定出缺陷能階的位置同時分析出缺陷的成因。因此，雙光源激發螢光光譜法在用來探討光學元件中的缺陷時可以說是相當有用的非破壞性檢測工具。In this thesis, we report an investigation of two-wavelength excited photoluminescence on InGaN/GaN multiple quantum wells to study the nonradiative defects. It is found that with an addition below-gap excitation the photoluminescence intensity can be quenched by up to 50%. In addition, the decay time of localized carriers changes from 173.9 ns to 7.9 ns. The quenching ratio depends on the power of the below-gap excitation. The experimental results can be well explained in terms of the electronic transitions involving deep defect states in the GaN barrier. Based on the variation of the photon energy of the below-gap excitation, the origin of the deep trap can be identified. We point out here that two wavelength excitation spectroscopy is a powerful non-destructive tool to reveal nonradiative defects in optoelectronic devices.Abstract in Chinese......i Abstract ......ii Figure Captions .......v Chapter 1 Introduction …………1 Reference …………5 Chapter 2 Theoretical Background ………………...7 2.1 Basics of Semiconductors …………………7 2.1.1 Band structure 7 2.1.2 Several recombination processes ……….9 2.1.3 Quantum confinement effect ………………12 2.2 Optical Measurements ......16 2.2.1 Photoluminescence ……………………16 2.2.2 Photoluminescence excitation ……16 2.2.3 Two wavelength excitation photoluminescence ………18 2.3 Time-resolved Measurement ....22 2.3.1 Introduction ……………22 2.3.2 Meaning of the lifetime or Decay time ……………22 2.3.3 Time-resolved PL apparatus ……25 Reference …………27 Chapter 3 Experimental Results and Discussion …28 3.1 Introduction ………28 3.2 Sample Structure ………28 3.3 Experimental Setup ……32 3.4 Results and Discussion ……35 3.4.1 PL, PLE, and TWEPL spectra ……35 3.4.2 Quantitative analysis of the transition ……43 3.4.3 TRPL results ……49 Reference ……53 Chapter 4 Conclusion ……543386069 bytesapplication/pdfen-US氮化銦鎵氮化鎵量子井螢光光譜InGaNGaNquantum wellPLthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/54522/1/ntu-96-R93222054-1.pdf