本論文探討以有機金屬化學氣相沉積法(MOCVD)成長之氮化銦鎵(包覆氮化銦鎵類量子點)/氮化鎵/氮化鋁鎵多重量子井(InGaN/GaN/AlGaN multiple quantum wells)之微結構與光學性質、電性質，其中氮化銦鎵類量子點即為氮化銦鎵於位能井層中，由於成長的氮化銦鎵位能井層時出現相分離的緣故導致氮化銦鎵薄膜出現銦富集區域如量子點一般的存在。本實驗利用高解析X光繞射(HRXRD)之ω-2θ 及ω-scan分析法解析薄膜之界面性質與結晶性；並藉由光激發光(PL)光譜量測進行不同溫度之分析，以及電激發光(EL)光譜量測進行不同電流之分析，從而了解銦富集之能帶情形以及光強度效率之影響。
本實驗依據研究主題可區分為四大部分。首先第一部分先探討紫外光380nm波長發光二極體之多重量子井結構的選擇，由大部分發光二極體所採用的氮化銦鎵/氮化鎵多重量子井結構改良，討論氮化銦鎵在短波長時需增加銦含量之相對應位能障層問題，將位能障層氮化鎵的部分換置成氮化鎵/氮化鋁鎵做搭配，並且同時發現銦富集的現象存在之分析。一般來說可由能帶圖分析出氮化鋁鎵位能障層的能隙大小相對於高銦含量的氮化銦鎵位能井層來說有較好的載子侷限能力，以增加載子複合機率，並且提高發光效率，然而本實驗選擇之氮化鎵/氮化鋁鎵之位能障層，不只考慮到這點更希望藉由氮化鋁鎵相對於氮化鎵的晶格常數較小所形成的伸張應力，補償氮化銦鎵相對於氮化鎵的晶格常數較大形成的壓縮應力，進而減少應力於材料中所造成的影響，但是本實驗在置換了位能障層之後，卻發現發光效率遞減，更進一步的產生多重波峰，因此本實驗之重點即為改善此部分之發現。
第二部分先對於位能障層氮化鎵/氮化鋁鎵的置換做進一步的分析，改變氮化鎵/氮化鋁鎵位能障層之厚度，並且將氮化鎵/氮化鋁鎵的搭配厚度做調整，觀察到其材料厚度調整將改善應力引起之銦富集現象和多重波峰之情形減少，以及由光激發光(PL)光譜知載子復合效率的提高。
第三部分則對於氮化銦鎵位能井層做分析，原因為由上述第二部分可知氮化鎵/氮化鋁鎵位能障層將會影量氮化銦鎵位能井層之銦富集現象，因此直接針對成長氮化銦鎵位能井層時之三甲基銦流量(TMIn)探討，觀察銦富集之分佈與改善是否會受其影響。藉由XRD分析可知在不影響銦含量增加太多的情形下，成長氮化銦鎵位能井層時提高三甲基銦流量(TMIn)將有效的改善銦組成，以及銦富集現象之減少，同樣由光激發光(PL)光譜知載子復合效率的改善。
第四部分將上述兩部份之分析結果結合成一新多重量子井結構，並且討論上述各部分之改良後多重量子井結構的發光二極體其電特性，藉由光激發光(PL)光譜、電流-電壓(I-V)特性圖、電流-光輸出(I-L)特性圖可知，成長氮化銦鎵位能井層時提高三甲基銦流量(TMIn)之改良比起將氮化鎵/氮化銦鎵位能障層的搭配厚度做調整之改良能夠更有效改善銦富集現象之影響，然而同時提高三甲基銦流量之氮化銦鎵位能井層與減少氮化鎵/氮化鋁鎵位能障層之厚度則有更加明顯的效益，因此判斷此兩種研究改良方法能夠確實的改變銦富集之現象，並且修正銦富集現象所引起之能帶不均勻之情形，大幅的提升發光功率以及載子復合行為。

We report the effect of strain-induced indium clustering on the emission properties of InGaN/GaN/AlGaN multiple quantum wells grown with high indium composition by metal-organic chemical vapor deposition. And anomalous emission behavior, specifically an S-shaped (decrease-increase-decrease) temperature dependence of the peak energy (Ep) for InGaN-related PL with increasing temperature: Ep redshifts in the temperature range of 20-50 K, blueshifts for 50-150 K, and redshifts again for 150-300 K with increasing temperature. In addition, We found that strong carrier localization in indium clustering induces the increases of the activation energy of PL integrated intensity, the temperature independence of PL decay profiles. All these observations suggest structurally and optically that the improved emission properties in the InGaN/GaN/AlGaN multiple quantum well with high indium composition are associated with the localized states in the strain induced indium cluster.

[1] 郭浩中、賴芳儀、郭守義, “LED原理與應用”, 五南圖書出版公司, 2012.
[2] 賴彥霖, “氮化銦鎵(類量子點)/氮化鎵多重量子井之微結構與光學性質之研究”, 國立成功大學材料科學及工程研究所, 博士論文, 2008.
[3] K. Osamura, K. Nakajima, and Y. Murakami, Solid State Commum. 11, 617, 1972.
[4] K. Osamura, S. Naka, and Y. Murakami, J. Appl. Phys. 46, 3432, 1975.
[5] C. Y. Hwang, “Growth and Characterization of Gallium Nitride on (0001) sapphire by Plasma Enhanced Atomic Layer Epitaxy and by Low Pressure Metaloganic Chemical Vapor Deposition ”, Ph.D. dissertation, Rutgers University, Piscataway, NJ, 1995.
[6] B.Gil, “Group III Nitride Semiconductor Compounds”, Oxford, New York, 1998.
[7] 史光國, “半導體發光二極體及固態照明”, 全華科技圖書股份有限公司, 2005。
[8] A. Y. Kim, W. Gӧtz, D. A. Steigerwald, J. J. Wierer, N. F. Gardner, J. Sun, S. A. Stockman, P. S. Martin, M. R. Krames, R. S. Kern, and F. M. Steranka, “Performance of high-power AlInGaN light emitting diodes,” phys. stat. sol. (a), vol. 188, pp. 15–21, 2001.
[9] C. Liu, W. N. Wang, P. A. Shields, S. Denchitcharoen, F. Causa, and D. E. W. Allsopp, “Improvement of efficiency droop in resonanace tunneling LEDs”, Proc. SPIE, vol. 7058, pp. 70580D-1–70580D-8, 2008.
[10] P. Bhattacharya, Semiconductor Optoelectronic Devices, Prentice Hall, Inc., 2nd ed. 1997.
[11] T.-M. Chou, User’s Manual for GAIN Program, Southern Methodist University, 2003.
[12] J. Singh, Electronic and Optoelectronic Properties of Semiconductor Structures, Cambridge University Press, 2003.
[13] H. Morkoc, “Nitride Semiconductors and Devices”, Springer-Verlag, Berlin, 1999.
[14] J. Piprek, Nitride Semiconductor Devices: Principles and Simulation, Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
[15] T. Takeuchi, S. Sota, M. Katsuragawa, M. Komori, H. Takeuchi, H. Amano, and I. Akasaki, “Quantum-confined Stark effect due to piezoelectric fields in GaInN strained quantum wells,” Jpn. J. Appl. Phys., vol. 36, pp. L382–L385, 1997.
[16] S. F. Chichibu, A. C. Abare, M. S. Minsky, S. Keller, S. B. Fleischer, J. E. Bowers, E. Hu, U. K. Mishra, L. A. Coldren, S. P. DenBaars, and T. Sota, “Effective band gap inhomogeneity and piezoelectric field in InGaN/GaN multiquantum well structures,” Appl. Phys. Lett., vol. 73, pp. 2006–2008, 1998.
[17] P. Waltereit, O. Brandt, A. Trampert, H. T. Grahn, J. Menniger, M. Ramsteiner, M. Reiche, and K. H. Ploog, “Nitride semiconductors free of electrostatic field for efficient white light-emitting diodes,” Nature, vol. 406, pp. 865–868, 2000.
[18] T. Takeuchi, C. Wetzel, S. Yamaguchi, H. Sakai, H. Amano, and I. Akasaki, “Determination of piezoelectric fields in strained GaInN quantum wells using the quantum-confined Stark effect,” Appl. Phys. Lett., vol. 73, pp. 1691–1693, 1998.
[19] S. De, A. Layek, S. Bhattacharya, D. K. Das, A. Kadir, A. Bhattacharya, S. Dhar, and A. Chowdhury, “Quantum-confined stark effect in localized luminescent centers within InGaN/GaN quantum-well based light emitting diodes,” Appl. Phys. Lett., vol. 101, pp. 121919-1–121919-5, 2012.
[20] E. Kuokstis, J. W. Yang, G. Simin, and M. A. Khan, “Two mechanisms of blueshift of edge emission in InGaN-based epilayers and multiple quantum wells,” Appl. Phys. Lett., vol. 80, pp. 977–979, 2002.
[21] I. Ho and G. B. Stringfellow, “Solid phase immiscibility in GaInN,” Appl. Phys. Lett. 69, 2701, 1996.
[22] S.Y. Karpov, “Suppression of phase separation in InGaN due to elastic strain,” MRS Internet J. Nitride Semicond. Res. 3, 16, 1998.
[23] M. K. Behbehani, E. L. Piner, S. X. Liu, N. A. EI-Masry, and S. M. Bedair, “Phase separation and ordering coexisting in InxGa1-xN grown by metal organic chemical vapor deposition,” Appl. Phys. Lett. 75, 2202, 1999.
[24] Y. T. Moon, D. j. Kim, J. S. Park, J. T. Oh, J. M. Lee, Y. W. Ok, H. Kim, and J. S. Park, “Temperature dependence of photoluminescence of InGaN films containing In-rich quantum dots,” Appl. Phys. Lett. 79, 599, 2001.
[25] H. K. Cho, J. Y. Lee, N. Sharma, C. J. Humphreys, G. M. Yang, C. S. Kim, J. H. Song, and P. W. Yu, “Effect of growth interruptions on the light emission and indium clustering of InGaN/GaN multiple quantum wells,” Appl. Phys. Lett. 79, 2594, 2001.
[26] M. Rao, D. Kim, and S. Mahajan, “Compositional dependence of phase separation in InGaN layers,” Appl. Phys. Lett. 85, 1961, 2004.
[27] I. K. Park, M. K. Kwon, S. H. Baek, Y. W. Ok, T. Y. Seong, S. J. Park, Y. S. Moon, and D. J. Kim, “Enhancement of phase separation in the InGaN layer for self-assembled In-rich quantum dots,” Appl. Phys. Lett. 87, 061906, 2005.
[28] T. M. Smeeton, M. J. Kappers, J. S. Barnard, M. E. Vickers, and C. J. Humphreys, “Electron-beam-induced strain within InGaN quantum wells: False indium “cluster” detection in the transmission electron microscope,” Appl. Phys. Lett. 83, 5419, 2003.
[29] J. P. O’Neill, I. M. Ross, A. G. Cullis, T. Wang, and P. J. Parbrook, “Electron-beam-induced segregation in InGaN/GaN multiple-quantum wells,” Appl. Phys. Lett. 83, 1965, 2003.
[30] S. Lazic, M. Moreno, J. M. Calleja, A. Trampert, K. H. Ploog, F. B. Naranjo, S. Fernaadez, and E. Calleja, “Resonant Raman scattering in strained and relaxed InGaN/GaN multi-quantum wells,” Appl. Phys. Lett. 86, 061905, 2005.
[31] J. Wagner, A. Ramakrishnan, H. Obloh, and M. Maier, “Effect of strain and associated piezoelectric fields in InGaN/GaN quantum wells probed by resonant Raman scattering,” Appl. Phys. Lett. 74, 3863, 1999.
[32] M. Stevens, A. Bell, M. R. McCartney, F. A. Ponce, H. Marui, and S. Tanaka, “ Effect of layer thickness on the electrostatic potential in InGaN quantum wells,” Appl. Phys. Lett. 85, 4651, 2004.
[33] J H Zhu, L J Wang, S M Zhang, H Wang, D G Zhao, J J Zhu, Z S Liu, D S Jiang, Y X Qiu, H Yang, “The investigation on strain relaxation and double peaks in photoluminescence of InGaN/GaN MQW layers,” Appl. Phys. Lett. 42, 2009.
[34] Y. H. Cho, G. H. Gainer, A. J. Fischer, J. J. Song, S. Keller, U. K. Mishra, and S. p. DenBaars, Appl. Phys. Lett. 73, 1970, 1998.
[35] 施敏、伍國珏,“半導體元件物理學第三版 pp.96”, 國立交通大學出版社, 2009.
[36] C. Y. Jia, C. T. Zhong, T. J. Yu, Z. Wang, Y. Z. Tong, and G. Y. Zhang, “Improvement of electrostatic discharge characteristics of InGaN/GaN MQWs light-emitting diodes by inserting an n+-InGaN electron injection layer and a p-InGaN/GaN hole injection layer”, Semicond. Sci. Technol., vol. 27, pp. 065008-1–065008-5, 2012.
[37] 劉俊男, “具有光子循環結構之氮化銦鎵/氮化鎵發光二極體其光電特性之探討”, 國立成功大學光電科學與工程學, 碩士論文, 2014.
[38] S. J. Chang, C. H. Kuo, Y. K. Su, L. W. Wu, J. K. Sheu, T. C. Wen, W. C. Lai, J. F. Chen,, and J. M. Tsai, “400-nm InGaN/GaN and InGaN/AlGaN Multiquantum Well Light-Emitting Diodes”, IEEE, vol. 8, 2002.
[39] Yong-Hoon Cho, G. H. Gainer, A. J. Fischer, J. J. Song, S. Keller, “S-shaped temperature-dependent emission shift and carrier dynamics in InGaN/GaN multiple quantum wells”, Appl. Phys. Lett. 73, 1370, 1998.
[40] H. K. Cho, J. Y. Lee, J. H. Song, P. W. Yu, G. M. Yang, and C. S. Kim, “Influence of strain-induced indium clustering on characteristics of InGaN/GaN multiple quantum wells with high indium composition”, Appl. Phys. Lett. 91, 1104, 2002.
[41] J. P. Perdew, A. Ruzsinszky, G. I. Csonka, O. A. Vydrov, G. E. Scuseria, L. A. Constantin, X. Zhou, and K. Burke, “Restoring the Density-Gradient Expansion for Exchange in Solids and Surfaces”, Phys. Rev. Lett. 100, 136406, 2008.
[42] g-Hyeon Kim, Hyeong-Soo Park, Yong-Jo Park, and Taeil Kim, “Formation of V-shaped pits in InGaN/GaN multiquantum wells and bulk InGaN films”, Appl. Phys. Lett. 73, 1634, 1998.