臺灣博碩士論文加值系統

此篇論文，致力於研究探討氮化鎵系發光二極體，隨著操作電流密度提升時，效率衰減 (efficiency droop)的現象，在第一章簡介部份，將簡單探討文獻上氮化鎵系發光二極體在效率衰減方面的相關研究。在第二章的部份，將對於主要的實驗儀器-有機金屬氣相化學沉積系統 (Metal-Organic Chemical Vapor Deposition, MOCVD)做簡單的介紹。另外，藉由改變不同磊晶條件的研究過程中，也逐步的探討了那些不是影響高電流下效率衰減的因素，而那些又是影響了外部量子效率 (External quantum efficiency, EQE)飽和點的電流發生位置，以及高電流密度操作下，造成效率衰減的主因，就主要結構的變化將其分為四個章節(第三章到第六章)，並逐步詳細的進行實驗分析與結果探討。
在第三章的部份，透過主動層 (active layer)磊晶結構的調整，探討了發光二極體從近紫外光波段至藍光波段下 (400~445 nm)，其元件效率衰減從小電流操作至1 A下的特性表現，透過此研究，發現壓電場 (piezoelectric field)、載子侷限 (carrier localized)對於元件在高電流下 (〉350 mA)的效率衰減影響不大，而是主要影響了在電流小於350 mA下的效率特性表現。另外，也推測歐傑效應 (Auger effect)並非大電流密度操作下，影響效率衰減的主因。
在第四章的部份，為了探討電洞注入效率對效率衰減特性的影響，藉由調整p型氮化鋁鎵電子阻檔層 (p-AlGaN electron blocking layer)的磊晶條件，設計了三種結構，發現三階梯式p-AlxGa1-xN EBL (x: 0.21, 0.14, 0.07)的發光二極體，在小電流下具有最高的外部量子效率表現，而三階梯式p-AlxGa1-xN EBL (x: 0.07, 0.14, 0.21)的發光二極體，雖然與參考片相比(p-AlxGa1-xN EBL, x: 0.21)，在小電流下的外部量子效率較低，但其外部量子效率的電流密度飽和點(指最大外部量子效率對應下的操作電流密度)是最大的，且隨著操作電流密度的提升，其效率衰減的幅度最小，其原因主要是因為(i) 由於三階梯式p-AlxGa1-xN EBL (x: 0.07, 0.14, 0.21)在價電帶 (valance bend)的能障 (barrier height)縮小，同時(ii)電子阻檔層內的內建電場也相對較小，因此有效提升電洞的注入效率，改善元件在高電流密度下的效率衰減情形。
在第五章的部份，將討論當多重量子井 (multiple quantum wells, MQWs)的barrier厚度不一樣時 (12, 8, 4 nm)，其元件在高電流密度注入下的效率衰減情形，發現窄barrier (4 nm)發光二極體不只有最大的電流密度飽和點，且其外部量子效率在操作電流密度200 Acm-2下，與傳統發光二極體 (barrier 12 nm)相比，有效提升了18 %，對於窄barrier (4 nm)發光二極體其效率衰減減緩的情形，透過另一項有趣的實驗設計，證實窄barrier (4 nm)發光二極體其載子能有效的均勻分佈，進而有效的提升主動層容納載子的空間，降低載子在主動層的密度。
在第六章的部份，嘗試在多重量子井的最後一個barrier與電子阻檔層間，分別插入5 nm厚的氮化鎵、氮化銦鎵、p型氮化銦鎵，並探討發光二極體對效率衰減特性的影響，發現所插入的氮化銦鎵與傳統氮化鎵相比，能有效的提高導電帶的能障，並降低導電帶的能障，此設計能有效的提升電子阻檔能力與電洞的注入效率，且p型氮化銦鎵的樣本，有著相當顯著的特性提升，其電流飽和點為316 mA且操作至1 A時，效率衰減只有7 %，這是因為有效的改善載子在主動層分佈不均的情形。
最後，我們將統整文獻上與本論文的研究，將主要影響EQE特性的因素分別在不同的電流密度區段 (stageⅠ.Ⅱ.Ⅲ)，做簡單的歸納與探討。

In this dissertation, the characteristics of efficiency droop under various current densities have been widely investigated. In the chapter one, we briefly discussed the leading causes of efficiency droop from literatures. In chapter two, the primary using machine–MOCVD (Metal-Organic Chemical Vapor Deposition) system was also being introduced. Subsequently, according to our structures design of epi-layers, the domination and subordination effects on efficiency droop were thoroughly studied and divided into four parts (chapter three to six).
In the chapter three, the wavelength-dependent InGaN-based light emitting diodes (LEDs) with peak emissions ranging from 400 to 445 nm, and investigated their efficiency-droop characteristics at injection currents of up to 1 A. It was found that the emissions of the wavelength-dependent InGaN LEDs underwent blue shifts at elevated currents. In addition, although the external quantum efficiencies (EQEs) changed dramatically when the critical current was less than 350 mA, the efficiency droop of each device exhibited a similar negative slope upon increasing the current from 350 mA to 1 A. Whereas the effects of piezoelectric polarization and different localized states in the active layer of the near-UV–to–blue LEDs influenced the peak EQEs and the dramatic decays of the EQE droops at lower injection currents, they were not responsible for the EQE droops at higher current levels. In addition, the piezoelectric effect and Auger non-radiative recombination were not dominating influences determining the efficiency droops of the wavelength-dependent LEDs at higher carrier densities.
In the chapter four, the EQE characteristics of InGaN/GaN light emitting diodes (LEDs) incorporating three-stepped AlGaN electron blocking layers (EBLs) were investigated. The LED featuring the three-stepped p-AlxGa1-xN EBL (x: 0.21, 0.14, 0.07) exhibited the highest EQE under low currents, but severe efficiency droop occurred upon increasing the current, relative to the performance of the reference LED incorporating a normal EBL (p-Al0.21GaN). In contrast, the LED with the three-stepped p-AlxGaN EBL (x: 0.07, 0.14, 0.21) displayed a notable improvement in its saturated peak efficiency at high current densities and mitigated efficiency droop upon elevating the injection current. The significant improvement in efficiency resulted from (i) an increase in the rate of hole injection upon decreasing the AlGaN barrier height of the valence band and (ii) the diminished built-in electric field after band-engineering with the three-stepped EBLs.
In the chapter five, we minimized efficiency droop by varying barrier thickness for InGaN/GaN multiple quantum wells (MWQs) featuring narrow quantum barriers (NQBs). The EQE for a light-emitting diode (LED) possessing NQBs improved by 18% at a current density of 200 A cm–2, compared to that of a conventional LED incorporating a 12-nm-thick barrier. The enhanced carrier distribution resulting from the presence of NQBs was practically approved from another experimental design in this study. We suggest that the NQBs displayed uniform carrier distribution in active layer and decreased the carrier density in the active layer at a critical current density.
In the chapter six, we observed a dramatic decrease in the efficiency droop of InGaN/GaN light-emitting diodes (LEDs) after positioning a p-InGaN insertion layer before the p-AlGaN electron-blocking layer (EBL). The saturated EQE of this device extended to 316 mA, with an efficiency droop of only 7% upon increasing the operating current to 1 A; in contrast, the corresponding conventional LED suffered a severe efficiency droop of 42%. We suspect that the asymmetric carrier distribution was effectively mitigated as a result of an improvement in the hole injection rate and a suppression of electron overflow.
Finally, we are going to conclude the leading effects on featuring EQEs in each stage, i.e. stage Ⅰ(under peak EQE), stage Ⅱ (peak EQE to 35 A cm-2) and stage Ⅲ (over 35 A cm-2). Furthermore, the state-of-the-art InGaN-based LED epi-structure is also demonstrated in chapter future work for the application of solid-state lighting.

Contents
Abstract (in Chinese) --------------------------------------------------------------- I
Abstract (in English) -------------------------------------------------------------- III
Acknowledgement ----------------------------------------------------------------- VI
Contents --------------------------------------------------------------------------- VIII
Table Captions ---------------------------------------------------------------------- XI
Figures Captions ------------------------------------------------------------------ XII

CHAPTER 1 Introduction --------------------------------------------------------- 1
1-1 Background -------------------------------------------------------------------- 1
1-2 Origin of efficiency droop ---------------------------------------------------------- 2
1-2-1 Junction heating --------------------------------------------------------------- 3
1-2-2 Auger recombination ---------------------------------------------------------- 4
1-2-3 Dislocations ------------------------------------------------------------------- 5
1-2-4 Carrier delocalization --------------------------------------------------------- 6
1-2-5 Carrier leakage --------------------------------------------------------------- 7
1-2-6 Poor hole injection efficiecny ------------------------------------------------ 8
Reference ------------------------------------------------------------------------------- 17
CHAPTER 2 Experimental equipment -------------------------------------- 23
2-1 Metal-Organic Chemical Vapor Deposition (MOCVD) system --------------------- 23
2-2-1 Design of MOCVD reactor -------------------------------------------------- 25
2.2-2 The mechanism of GaN growth on sapphire substrate ----------------------- 26
Reference ------------------------------------------------------------------------------- 35

CHAPTER 3 The efficiency droop characteristics of near-ultraviolet to blue emitting InGaN-LEDs ----------------------------------------------------- 36
3-1 Motivation --------------------------------------------------------------------------36
3-2 Experiment details ------------------------------------------------------------------ 37
3-3 Structure analysis by HRXRD ------------------------------------------------------ 38
3-4 Characteristics of external quantum efficiency in wavelength-dependent LEDs ---- 39
3-5 QCSE effect in wavelength-dependent LEDs --------------------------------------- 40
3-6 Evaluation of external quantum efficiency in wavelength-dependent LEDs --------- 41
3-7 Investigation of efficiency droop in wavelength-dependent LEDs ------------------ 42
3-4 Summary --------------------------------------------------------------------------- 43
Reference ------------------------------------------------------------------------------- 48

CHAPTER 4 Characteristics of efficiency droop in GaN-based light emitting diodes with an AlGaN staircase electron blocking layer -------- 50
4-1 Motivation -------------------------------------------------------------------------- 50
4-2 Experiment details ------------------------------------------------------------------ 51
4-3 EQEs behavior discussion at low current density ----------------------------------- 52
4-4 EQEs behavior discussion at high current density ----------------------------------- 54
4-5 Summary --------------------------------------------------------------------------- 56
Reference ------------------------------------------------------------------------------- 61

CHAPTER 5 Improved carrier distributions by varying barrier thickness for InGaN/GaN LEDs ----------------------------------------------- 62
5-1 Motivation -------------------------------------------------------------------------- 62
5-2 Experiment details ------------------------------------------------------------------ 63
5-3 EQEs behavior of InGaN/GaN LEDs featuring quantum barriers of various thicknesses ------------------------------------------------------------------------------------------ 65
5-4 EL peak positions of InGaN/GaN LEDs with respect to the current density --------- 66
5-5 Discussion of carrier distribution with LEDs A and B ------------------------------- 67
5-6 Summary --------------------------------------------------------------------------- 69
Reference ------------------------------------------------------------------------------- 76

CHAPTER 6 Inserting a p-InGaN layer before the p-AlGaN EBL suppresses efficiency droop in InGaN-based LEDs ------------------------- 80
6-1 Motivation -------------------------------------------------------------------------- 80
6-2 Experiment details ------------------------------------------------------------------ 81
6-3 Band diagrams simulation ---------------------------------------------------------- 82
6-4 Discussion of EQEs behavior ------------------------------------------------------- 83
6-5 Forward and reverse I-V characteristics --------------------------------------------- 84
6-6 SIMS profile of GaN LED and p-InGaN LED -------------------------------------- 85
6-6 Summary --------------------------------------------------------------------------- 86
Reference ------------------------------------------------------------------------------- 89

CHAPTER 7 Conclusion and Future work ---------------------------------- 91
7-1 Conclusion -------------------------------------------------------------------------- 91
7-2 Future work ------------------------------------------------------------------------- 94 Reference ------------------------------------------------------------------------------- 98

Ch1:
[1] Shuji Nakamura, Masayuki Senoh, Naruhito Iwasa, Shin-ichi Nagahama, Jpn. J. Appl. Phys. 34, L797-L799 (1995).
[2] Shuji Nakamura, Masayuki Senoh, Shin‐ichi Nagahama, Naruhito Iwasa, Takao Yamada, Toshio Matsushita, Yasunobu Sugimoto, and Hiroyuki Kiyoku, Appl. Phys. Lett. 69, 4056 (1996).
[3] Shuji Nakamura, Naruhito Iwasa, Masayuki Senoh. “Method of manufacturing p-type compound semiconductor US patent 5,306,662 (1994)
[4] E. Fred Schubert. “Light-Emitting Diodes (2003)
[5] Shuji Nakamura and Gerhard Fasol. “The Blue Laser Diode (Springer, Berlin, 1997)
[6] Ansgar Laubsch, Matthias Sabathil, Johannes Baur, Matthias Peter, and Berthold Hahn, IEEE Trans. Electron Devices 57, 79 (2010).
[7] M. Peter, A. Laubsch, W. Bergbauer, T. Meyer, M. Sabathil, J. Baur and B. Hahn, Phys. Status Solidi A 6, 1 (2009).
[8] T. Mukai, M. Yamada, and S. Nakamura, Jpn. J. Appl. Phys. Part 1 38, 3976–3981 (1999).
[9] Y. Yang, X. A. Cao, and C. Yan, IEEE Trans. Electron Devices 55, 1771 (2008).
[10] W. Sun, M. Shatalov, J. Deng, X. Hu, J. Yang, A. Lunev, Y. Bilenko, M. Shur, and R. Gaska, Appl. Phys. Lett. 96, 061102 (2010).
[11] H. Hirayama, S. Fujikawa, N. Noguchi, J. Norimatsu, T. Takano, K. Tsubaki, and N. Kamata, Phys. Status Solidi A 206, 1176 (2009).
[12] A. Laubsch, M. Sabathil, W. Bergbauer, M. Strassburg, H. Lugauer, M. Peter, S. Lutgen, N. Linder, K. Streubel, J. Hader, J. V. Moloney, B. Pasenow, and S. W. Koch, Phys. Status Solidi C 6, S913 (2009).
[13] A. Laubsch et al., Phys. Status Solidi C 6, S913 (2009).
[14] A. A. Efremov, N. I. Bochkareva, R. I. Gorbunov, D. A. Lavrinovich, Yu. T. Rebane, D. V. Taekhin and Yu. G. Shreter, Semiconductors 40, 605 (2006).
[15] M. H. Kim, M. F. Schubert, Q. Dai, J. K. Kim, E. F. Schubert, J. Piprek and Y. Park, Appl. Phys. Lett. 91, 183507 (2007).
[16] K. Fujiwara, H. Jimi and K. Kaneda, Phys. Status Solidi C 6, S814 (2009).
[17] X. Li, J. Lee, M. Wu, ¨U. ¨Ozg¨ur, H. Morko¸c, T. Paskova, G. Mulholland and K. R. Evans, Appl. Phys. Lett. 95, 121107 (2009).
[18] Y.-D. Lin, A. Chakraborty, S. Brinkley, H, C. Kuo, T. Melo, K. Fujito, J. S. Speck, S. P. DenBaars and S. Nakamura, Appl. Phys. Lett. 94, 261108 (2009).
[19] N. F. Gardner, G. O. M¨uller, Y. C. Shen, G. Chen, S. Watanabe, W. G¨otz and M. R. Krames, Appl. Phys. Lett. 91, 243506 (2007).
[20] A. Y. Kim, W. Götz, D. A. Seigerwald, J. J. Wierer, N. F. Gardner, J. Sun, S. A. Stockman, P. S. Martin, M. R. Krames, R. S. Kern, and F. M. Steranka, Phys. Status Solidi A 188, 15 (2001).
[21] S. Nakamura, M. Senoh, N. Iwasa, and S. Nagahama, Jpn. J. Appl. Phys., Part 2 34, L797 (1995).
[22] A. A. Efremov, N. I. Bochkareva, R. I. Gorbunov, D. A. Lavrinovich, Yu. T. Rebane, D. V. Taekhin and Yu. G. Shreter, Semiconductors 40, 605 (2006).
[23] Oskari Heikkilä, Jani Oksanen, and Jukka Tulkki, J. Appl. Phys. 107, 033105 (2010).
[24] I. V. Rozhansky and D. A. Zakheim, Semiconductors 40, 839 (2006).
[25] I. V. Rozhansky and D. A. Zakheim, Phys. Status Solidi A 204, 227 (2007).
[26] Jun Ho Son and Jong-Lam Lee, Appl. Phys. Lett. 97, 032109 (2010).
[27] J. Xu, M. F. Schubert, A. N. Noemaun, D. Zhu, J. K. Kim, E. F. Schubert, M. H. Kim, H. J. Chung, S. Yoon, C. Sone, and Y. Park, Appl. Phys. Lett. 94, 011113 (2009).
[28] M. F. Schubert, J. Xu, J. K. Kim, E. F. Schubert, M. H. Kim, S. Yoon, S. M. Lee, C. Sone, T. Sakong, and Y. Park, Appl. Phys. Lett. 93, 041102 (2008).
[29] K. J. Vampola, M. Iza, S. Keller, S. P. DenBars, and S. Nakamura, Appl. Phys. Lett. 94, 061116 (2009).
[30] Suk Choi, Hee Jin Kim, Seong-Soo Kim, Jianping Liu, Jeomoh Kim, Jae-Hyun Ryou, Russell D. Dupuis,Alec M. Fischer, and Fernando A. Ponce, Appl. Phys. Lett. 96, 221105 (2010).
[31] Y. C. Shen, G. O. Mueller, S. Watanabe, N. F. Gardner, A. Munkholm, and M. R. Krames, Appl. Phys. Lett. 91, 141101 (2007).
[32] J. Harder, J. V. Moloney, B. Pasenow, S. W. Koch, M. Sabathil, N. Linder and S. Lutgen, Appl. Phys. Lett. 92, 261103 (2008).
[33] J. Hader, J. V. Moloney, and S. W. Koch, Appl. Phys. Lett. 99, 181127 (2011)
[34] K. T. Delaney, P. Rinke, and C. G. Van de Walle, Appl. Phys. Lett. 94, 191109 (2009).
[35] M. Zhang, P. Bhattacharya, J. Singh, and J. Hinkley, Appl. Phys. Lett. 95, 201108 (2009).
[36] K. A. Bulashevich and S. Yu. Karpov, Phys. Status Solidi C 5, 2066 (2008).
[37] B. Pasenow, S. W. Koch, J. Hader, J. V. Moloney, M. Sabathil, N. Linder, and S. Lutgen, Phys. Status Solidi C 6, S864 (2009).
[38] E. Kioupakis, P. Rinke, K. T. Delaney, and C. G. Van de Walle, Appl. Phys. Lett. 98, 161107 (2011).
[39] W. A. Phillips, E. J. Thrush, Y. Zhang, and C. J. Humphreys, Phys. Status Solidi C, 1– 5 (2012).
[40] S.-H. Yen, M.-C. Tsai, M.-L. Tsai, Y.-J. Shen, T.-C. Hsu, and Y.-K. Ku, Appl Phys A 97 705–708 (2009).
[41] J.-R. Chen, Y.-C. Wu, S.-C. Ling, T.-S. Ko, T.-C. Lu, H.-C. Kuo, Y.-K. Kuo, and S.-C. Wang, Appl Phys B 98 779–789 (2010).
[42] S. F. Chichibu, T. Azuhata, M. Sugiyama, T. Kitamura, Y. Ishida, H. Okumura, H. Nakanishi, T. Sota, and T. Mukai, J. Vac. Sci. Technol. B 19, 2177 (2001).
[43] B. Monemar and B. E. Sernelius, Appl. Phys. Lett. 91, 181103 (2007).
[44] A. Hangleiter, D. Fuhrmann, M. Grewe, F. Hitzel, G. Klewer, S. Lahmann, C. Netzel, N. Riedel, and U. Rossow, phys. stat. sol. (a) 201, No. 12, 2808 (2004).
[45] B. Monemar and B. E. Sernelius, Appl. Phys. Lett. 91, 181103 (2007).
[46] J. Harder, J. V. Moloney and S. W. Koch, Appl. Phys. Lett. 96, 261106 (2010).
[47] N. I. Bochkareva, V. V. Voronenkov, R. I. Gorbunov, A. S. Zubrilov, Y. S. Lelikov P. E. Latyshev, Y. T. Rebane, A. I. Tsyuk, and Y. G. Shreter, Appl. Phys. Lett. 96, 133502 (2010).
[48] X. Ni, Q. Fan, R. Shimada, ¨U. ¨Ozg¨ur and H. Morko¸c, Appl. Phys. Lett. 93, 071113 (2008).
[49] J. Xie, X. Ni, Q. Fan, R. Shimada, Ü. Özgür, and H. Morkoc, Appl. Phys. Lett. 93, 121107 (2008).
[50] K. A. Bulashevich, M. S. Ramm, and S. Yu. Karpov, Phys. Status Solidi C 6, S804 (2009).
[51] I. A. Pope, P. M. Smowton, P. Blood, J. D. Thomson, M. J. Kappers, and J. Humphreys, Appl. Phys. Lett. 82, 27551 (2003).
[52] S. H. Han, D. Y. Lee, S. J. Lee, C. Y. Cho,M. K. Kwon, S. P. Lee, D. Y. Noh, D. J. Kim, Y. C. Kim, and S. J. Park, Appl. Phys. Lett. 94, 2311231 (2009).
[53] Yen-Kuang Kuo, Miao-Chan Tsai, Sheng-Horng Yen, Ta-Cheng Hsu, and Yu-Jiun Shen, IEEE JOURNAL OF QUANTUM ELECTRONICS, 46, NO. 8, 1214 (2010).
[54] L. Zhang, K. Ding, N. X. Liu, T. B. Wei, X. L. Ji, P. Ma, J. C. Yan, J. X. Wang,
Y. P. Zeng, and J. M. Li, Appl. Phys. Lett. 98, 101110 (2011).
[55] Yen-Kuang Kuo, Jih-Yuan Chang, and Miao-Chan Tsai, OPTICS LETTERS 35, 3285 (2010).
[56] Sang-Jun Lee, Sang-Heon Han, Chu-Young Cho, S P Lee, D Y Noh, Hyun-Wook Shim, Yong Chun Kim and Seong-Ju Park, J. Phys. D: Appl. Phys. 44, 105101 (2011).
[57] C. H. Wang, C. C. Ke, C. Y. Lee, S. P. Chang, W. T. Chang, J. C. Li, Z. Y. Li, H. C. Yang, H. C. Kuo, T. C. Lu, and S. C. Wang, Appl. Phys. Lett. 97, 26110 (2010).
[58] E. H. Park, D. N. H. Kang, I. T. Ferguson, S. K. Jeon, J. S. Park, and T. K. Yoo, Appl. Phys. Lett. 90, 031102 (2007).
[59] J. H. Ryou, J. Limb, W. Lee, J. Liu, Z. Lochner, D. Yoo, and R. D. Dupuis, IEEE Photon. Technol. Lett. 20, 1769–1771 (2008).
[60] A. David, M. J. Grundmann, J. F. Kaeding, N. F. Gardner, T. G. Mihopoulos, and M. R. Krames, Appl. Phys. Lett. 92, 053502 (2008).
[61] H. Y. Ryu, and K. H. Ha, Opt. Express 16, 10849–10857 (2008).
[62] U. Kaufmann, P. Schlotter, H. Obloh, K. Köhler, and M. Maier, Phys. Rev. A 62 (2000) 10867
[63] Guan-Bo Lin, David Meyaard, Jaehee Cho, E. Fred Schubert, Hyunwook Shim, and Cheolsoo Sone, Appl. Phys. Lett. 100, 161106 (2012).
[64] Dong-Soo Shin, Dong-Pyo Han, Ji-Yeon Oh, and Jong-In Shim, Appl. Phys. Lett. 100, 153506 (2012).
[65] Jiaxing Wang, Lai Wang, Wei Zhao, Zhibiao Hao, and Yi Luo, Appl. Phys. Lett. 97, 201112 (2010).
[66] Joachim Piprek, Phys. Status Solidi A 207, 2217–2225 (2010).
[67] J. Piprek, Semiconductor Optoelectronic Devices: Introduction to Physics and Simulation (Academic Press, San Diego, 2003).
[68] J. Piprek, P. Abraham, and J. E. Bowers, IEEE J. Quantum Electron. 36, 366 (2000).
[69] A. D. Dra¨ger, H. Jo¨nen, C. Netzel, U. Rossow, and A. Hangleiter, 8th International Conference on Nitride Semiconductors, Jeju (2009).
[70] M. Meneghini, N. Trivellin, G. Meneghesso, and E. Zanoni, J. Appl. Phys. 106, 114508 (2009).
[71] Martin F. Schubert, Sameer Chhajed, Jong Kyu Kim, and E. Fred Schubert, Appl. Phys. Lett. 91, 231114 (2007).
[72] K. B. Nam, M. K. Nakarmi, J. Li, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 83, 878 (2003).
[73] Dmitry S. Sizov, Rajaram Bhat,Aramais Zakharian, Kechang Song, Donald E. Allen, Sean Coleman, and Chung-en Zah, IEEE J. Sel. Top. Quantum Electron., 17, NO. 5, 1390 (2011).
[74] Sang-Heon Han, Dong-Yul Lee, Sang-Jun Lee, Chu-Young Cho, Min-Ki Kwon, S. P. Lee, D. Y. Noh, Dong-Joon Kim, Yong Chun Kim, and Seong-Ju Park, Appl. Phys. Lett. 94, 231123 (2009).
Ch2:
[1] H.M. Manasevt, Journal of Crystal Growth, no. 13-14 306-314 (1972).
[2] M. yano, H. Nishi, and M. Tkusagawa, J. Appl. Phys., Vol. 51, 4022 (1980)
[3] Patrick Mottier, Ch.2. Substrates for Ⅲ-Nitride-based Electroluminescent Diodes, “LEDs for Lighting Applications, (ISBN: 978-1-84821-145-2) (2009).
[4] Akinori Koukitu, Naoyuki Takahashi and Hisashi Seki, Jpn. J. Appl. Phys., 36 L1136-L1138 (1997).
[5] M. yano, H. Nishi, and M. Tkusagawa, J. Appl. Phys., 51, 4022 (1980)
[6] H. Tokunaga, A. Ubukata, Y. Yano, A. Yamaguchi, N. Akutsu, T. Yamasaki, K. Matsumoto, J. Cryst. Growth 272, 3348 (2004).
[7] A. Watanabe, H. Takahashi, T. Tanaka, H. Ota, K. Chikuma, H. Amano, T. Kashima, R. Nakamura, I. Akasaki, Jpn. J. Appl. Phys. 38, L1159 (1999)
[8] P. Finni, X. Wu, E.J. Tarsa, Y. Golan, V. Srikant, S. Keller, S.P. DenBaars, J.S. Speck, Jpn. J. Appl. Phys. 37, 4460 (1998)
[9] J. Chang, S.-K. Hong, K. Matsumoto, H. Tokunaga, A. Tachibana, S.W. Lee, and M.-W. Cho, s, Ch.3. Growth of ZnO and GaN Films, “Oxide and Nitride Semiconductor, (ISBN: 978-3-540-88846-8) (2009).
[10] James D. Plummer, Michael D. Deal, and B. Griffin, 9.2.1 Chemical Vapor Deposition (CVD), “Silicon VLSI Technology Fundamentals, Practice and Modeling, (ISBN: 0-13-178458-7) (2000).
Ch3:
[1] E. Kioupakis, P. Rinke, K. T. Delaney, and C. G. Van de Walle: Appl. Phys. Lett. 98, 161107 (2011).
[2] S. Choi, H. J. Kim, S.-S. Kim, J. Liu, J. Kim, J.-H. Ryou, R. D. Dupuis, A. M. Fischer, and F. A. Ponce: Appl. Phys. Lett. 96, 221105 (2010).
[3]X. A. Cao, S. F. LeBoeuf, M. P. D’Evelyn, S. D. Arthur, J. Kretchmer, C. H. Yan, and Z. H. Yang: Appl. Phys. Lett. 84, 4314 (2004).
[4] B. Monemar and B. E. Sernelius: Appl. Phys. Lett. 91, 181103 (2007).
[5] Y. Yang, X. A. Cao, and C. Yan: IEEE Trans. Electron Devices 55, 1771 (2008).
[6] S.-H. Han, D.-Y. Lee, S.-J. Lee, C.-Y. Cho, M.-K. Kwon, S. P. Lee, D. Y. Noh, D.-J. Kim, Y. C. Kim, and S.-J. Park: Appl. Phys. Lett. 94, 231123 (2009).
[7] S.-J. Lee, S.-H. Han, C.-Y. Cho, S. P. Lee, D. Y. Noh, H.-W. Shim, Y. C. Kim, and S.-J. Park: J. Phys. D: Appl. Phys. 44, 105101 (2011).
[8] L. Zhang, K. Ding, N. X. Liu, T. B. Wei, X. L. Ji, P. Ma, J. C. Yan, J. X. Wang, Y. P. Zeng, and J. M. Li: Appl. Phys. Lett. 98, 101110 (2011).
[9] M.-H. Kim, M. F. Schubert, Q. Dai, J. K. Kim, E. F. Schubert, J. Piprek, and Y. Park: Appl. Phys. Lett. 91, 183507 (2007).
[10] M. F. Schubert and E. F. Schubert: Appl. Phys. Lett. 96, 131102 (2010).
[11] M. Baeumler, M. Kunzer, R. Schmidt, S. Liu, W. Pletschen, P. Schlotter, K. Köhler, U. Kaufmann, and J. Wagner: Phys. Status Solidi A 204, 1018 (2007).
[12] X. A. Cao, S. F. LeBoeuf, L. B. Rowland, C. H. Yan, and H. Liu: Appl. Phys. Lett. 82, 3614 (2003).
[13] J.-R. Chen, Y.-C. Wu, S.-C. Ling, T.-S. Ko, T.-C. Lu, H.-C. Kuo, Y.-K. Kuo, and S.-C. Wang: Appl. Phys. B 98, 779 (2010).
[14] Y. C. Shen, G. O. Mueller, S. Watanabe, N. F. Gardner, A. Munkholm, and M. R. Krames: Appl. Phys. Lett. 91, 141101 (2007).
[15] K. T. Delaney, P. Rinke, and C. G. Van de Walle: Appl. Phys. Lett. 94, 191109 (2009).
Ch4:
[1] M. H. Kim, M. F. Schubert, Q. Dai, J. K. Kim, E. F. Schubert, J. Piprek, and Y. Park, Appl. Phys. Lett. 91,183507 (2007).
[2] B. Monemar and B. E. Sernelius, Appl. Phys. Lett. 91, 181103 (2007).
[3] E. Kioupakis, P. Rinke, K. T. Delaney, and C. G. Van de Walle, Appl. Phys. Lett. 98, 161107 (2011).
[4] L. Zhang, K. Ding, N. X. Liu, T. B. Wei, X. L. Ji, P. Ma, J. C. Yan, J. X. Wang, Y. P. Zeng, and J. M. Li, Appl. Phys. Lett. 98, 101110 (2011).
[5] I. V. Rozhansky and D. A. Zakheim, Phys. Status Solidi A 204, 227 (2007).
[6] W. Götz, N. M. Johnson, C. Chen, H. Liu, C. Kuo, and W. Imler, Appl. Phys. Lett. 68, 3144 (1996).
[7] J. K. Sheu and G. C. Chi, J. Phys.: Condens. Matter 14, R657–R702 (2002).
[8] S.-H. Han, D.-Y. Lee, S.-J. Lee, C.-Y. Cho, M.-K. Kwon, S. P. Lee, D. Y. Noh, D.-J. Kim, Y. C. Kim, and S.-J. Park, Appl. Phys. Lett. 94, 231123 (2009).
[9] S. Choi, H. J. Kim, S.-S. Kim, J. Liu, J. Kim, J.-H. Ryou, R. D. Dupuis, A. M. Fischer, and F. A. Ponce, Appl. Phys. Lett. 96, 221105 (2010).
[10] Y.-K. Kuo, J.-Y. Chang, and M.-C. Tsa, Opt. Lett. 35, 3285 (2010).
[11] L. Zhang, K. Ding, N. X. Liu, T. B. Wei, X. L. Ji, P. Ma, J. C. Yan, J. X. Wang, Y. P. Zeng, and J. M. Li, Appl. Phys. Lett. 98, 101110 (2011).
[12] C. H. Wang, C. C. Ke, C. Y. Lee, S. P. Chang, W. T. Chang, J. C. Li, Z. Y. Li, H. C. Yang, H. C. Kuo, T. C. Lu, and S. C. Wang, Appl. Phys. Lett. 97, 261103 (2010).
[13] C. L. Reynolds, Jr., and A. Patel, J. Appl. Phys. 103, 086102 (2008).
[14] O. Ambacher, J. Smart, J. R. Shealy, N. G. Weimann, K. Chu, M. Murphy, W. J. Schaff, and L. F. Eastman, J. Appl. Phys. 85, 3222 (1999).
[15] F. Bernardini, V. Fiorentini, and D. Vanderbilt, Phys. Rev. B 56, 10024 (1997).
Ch5:
[1] A. Laubsch, M. Sabathil, J. Baur, M. Peter, and B. Hahn, “High-power and high-efficiency InGaN-based light emitters, IEEE Trans. Electron Dev., vol. 57, pp. 79-87, 2010.
[2] E. Kioupakis, P. Rinke, K. T. Delaney, and C. G. Van de Walle, “Indirect Auger recombination as a cause of efficiency droop in nitride light-emitting diodes, Appl. Phys. Lett., vol. 98, Art. no. 161107, 2011.
[3] J. Hader, J. V. Moloney, B. Pasenow, S. W. Koch, M. Sabathil, N. Linder, and S. Lutgen, “On the importance of radiative and Auger losses in GaN-based quantum wells, Appl. Phys. Lett., vol. 92, Art. no. 261103, 2008.
[4] K. T. Delaney, P. Rinke, and C. G. Van de Walle, Appl. Phys. Lett., “Auger recombination rates in nitrides from first principles, vol. 94, Art. no. 191109, 2009.
[5] M. F. Schubert, J. R. Xu, Q. Dai, F. W. Mont, J. K. Kim, and E. F. Schubert, “On resonant optical excitation and carrier escape in GaInN/GaN quantum wells, Appl. Phys. Lett., vol. 94, Art. no. 081114, 2009.
[6] X. Li, H. Y. Liu, X. Ni, Ü. Özgür, and H. Morkoç, “Effect of carrier spillover and Auger recombination on the efficiency droop in InGaN-based blue LEDs, Superlattices Microstruct., vol. 47, pp. 118-122, 2010.
[7] R. M. Farrell, E. C. Young, F. Wu, S. P. DenBaars, and J. S. Speck, “Materials and growth issues for high-performance nonpolar and semipolar light-emitting devices“, Semicond. Sci. Technol., vol. 27, Art. no. 024001, 2012.
[8] R. M. Farrell, D. A. Haeger, P. S. Hsu, K. Fujito, D. F. Feezell, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Determination of internal parameters for AlGaN-cladding-free m-plane InGaN/GaN laser diodes, Appl. Phys. Lett., vol. 99, Art. no. 171115, 2011.
[9] H. P. Zhao, G. Y. Liu, J. Zhang, J. D. Poplawsky, V. Dierolf, and N. Tansu, “Approaches for high internal quantum efficiency green InGaN light-emitting diodes with large overlap quantum wells, Opt. Express, vol. 19, pp. A991-A1007, 2011.
[10] H. P. Zhao, G. Y. Liu, and N. Tansu, “Analysis of InGaN-delta-InN quantum wells for light-emitting diodes, Appl. Phys. Lett., vol. 97, Art. no. 131114, 2010.
[11] J. Zhang and N. Tansu, “Improvement in spontaneous emission rates for InGaN quantum wells on ternary InGaN substrate for light-emitting diodes, J. Appl. Phys., vol. 110, Art. no. 113110, 2011.
[12] Y. K. En, J. M. Biser, W. Cao, H. M. Chan, R. P. Vinci, and N. Tansu, “Metalorganic vapor phase epitaxy of III-nitride light-emitting diodes on nanopatterned AGOG sapphire substrate by abbreviated growth mode, IEEE J. Sel. Topic on Quan. Electron., vol. 15, pp. 1066-1072, 2009
[13] Y. K. En, X. H. Li, J. Biser, W. J. Cao, H. M. Chan, R. P. Vinci, and N. Tansu, “Abbreviated MOVPE nucleation of III-nitride light-emitting diodes on nano-patterned sapphire, J. Crystal Growth, vol. 312, pp. 1311-1315, 2010.
[14] Y. F. Li, S. You, M. W. Zhu, L. Zhao, W. T. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel,, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire, Appl. Phys. Lett., vol. 98, Art. no. 151102, 2011.
[15] T. S. Kim, B. J. Ahn, Y. Q. Dong, K. N. Park, J. G. Lee, Y. B. Moon, H. K. Yuh, S. C. Choi, J. H. Lee, S. K. Hong, and J. H. Song, “Well-to-well non-uniformity in InGaN/GaN multiple quantum wells characterized by capacitance-voltage measurement with additional laser illumination, Appl. Phys. Lett., vol. 100, Art. no. 071910, 2012.
[16] W. W. Chow, M. H. Crawford, J. Y. Tsao, and M. Kneissl, “Internal efficiency of InGaN light-emitting diodes: beyond a quasiequilibrium model, Appl. Phys. Lett., vol. 97, Art. no. 121105, 2010.
[17] N. F. Gardner, G. O. Müller, Y. C. Shen, G. Chen, S. Watanabe, W. Götz, and M. R. Krames, “Blue-emitting InGaN-GaN double-heterostructure light-emitting diodes reaching maximum quantum efficiency above 200 A/cm2, Appl. Phys. Lett., vol. 91, Art. no. 243506, 2007.
[18] M. Maier, K. Köhler, M. Kunzer, W. Pletschen, and J. Wagner, “Reduced nonthermal rollover of wide-well GaInN light-emitting diodes, Appl. Phys. Lett., vol. 94, Art. no. 041103, 2009.
[19] H. P. Zhao, G. Y. Liu, R. A. Arif, and N. Tansu, “Current injection efficiency induced efficiency-droop in InGaN quantum well light-emitting diodes, Solid-State Electron., vol. 54, pp. 1119–1124, 2010.
[20] A. David, M. J. Grundmann, J. F. Kaeding, N. F. Gardner, T. G. Mihopoulos, and M. R. Krames, “Carrier distribution in (0001)InGaN/GaN multiple quantum well light-emitting diodes, Appl. Phys. Lett., vol. 92, Art. no. 053502, 2008.
[21] U. Kaufmann, P. Schlotter, H. Obloh, K. Köhler, and M. Maier, “Hole conductivity and compensation in epitaxial GaN : Mg layers, Phys. Rev. B, vol. 62, pp. 10867-10872, 2000.
[22] D. A. Zakheim, A. S. Pavluchenko, D. A. Bauman, K. A. Bulashevich, O. V. Khokhlev, and S. Yu. Karpov, “Efficiency droop suppression in InGaN-based blue LEDs: Experiment and numerical modelling, Physica Status Solidi A, vol. 209, pp. 456-460, 2012.
[23] B. C. Chen, C. Y. Chang, Y. K. Fu, K. F. Huang, Y. H. Lu, and Y. K. Su, “Improved performance of InGaN/GaN light-emitting diodes with thin intermediate barriers, IEEE Photon. Technol. Lett., vol. 23, pp. 1682-1684, 2011.
[24] M. C. Tsai, S. H. Yen, Y. C. Lu, and Y. K. Kuo, “Numerical Study of blue InGaN light-emitting diodes with varied barrier thicknesses, IEEE Photon. Technol. Lett., vol. 23, pp. 76-78, 2011.
Ch6:
[1] N. F. Gardner, G. O. Müller, Y. C. Shen, G. Chen, S. Watanabe, W. Götz, and M. R. Krames, Appl. Phys. Lett. 91 243506 (2007).
[2] X. Ni, Q. Fan, R. Shimada, Ü. Özgür, and H. Morkoç, Appl. Phys. Lett. 93 171113 (2008).
[3] D. S. Meyaard, G.-B. Lin, Q. Shan, J. Cho, E. F. Schubert, H. Shim, M.-H. Kim, and C. Sone, Appl. Phys. Lett. 99 251115 (2011).
[4] M. F. Schubert, J. Xu, J. K. Kim, E. F. Schubert, M. H. Kim, S. Yoon, S. M. Lee, C. Sone, T. Sakong, and Y. Park, Appl. Phys. Lett. 93 041102 (2008).
[5] M.-H. Kim, M. F. Schubert, Q. Dai, J. K. Kim, E. F. Schubert, J. Piprek, and Y. Park, Appl. Phys. Lett. 91 183507 (2007)
[6] I. V. Rozhansky and D. A. Zakheim, Phys. Stat. Sol. (c) 3 2160 (2006).
[7] J. Xie, X. Ni, Q. Fan, R. Shimada, Ü. Özgür, and H. Morkoç, Appl. Phys. Lett. 93 121107 (2008).
[8] X. Ni, Q. Fan, R. Shimada, Ü. Özgür, and H. Morkoç, Appl. Phys. Lett. 93 171113 (2008).
[9] K. Kumakura, T. Makimoto, and N. Kobayashi, J. Appl. Phys. 93 3370 (2003).
[10] T. Tanaka, A. Watanabe, H. Amano, Y. Kobayashi, I. Akasaki, S. Yamazaki, and M. Koile, Appl. Phys. Lett. 65 593 (1994).
[11] J. Li, T. N. Oder, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 80 1210 (2002).
[12] L. Wang, H. Li, G. Xi, Y. Jiang, W. Zhao, Y. Han, and Y. Luo, Jpn. J. Appl. Phys. 47 7101 (2008).
[13] Y.-K. Kuo, M.-C. Tsai, S.-H. Yen, T.-C. Hsu, and Y.-J. Shen, IEEE J. Quantum Electron. 46 1214 (2010).
[14] X. A. Cao, E. B. Stokes, P. M. Sandvik, S. F. LeBoeuf, J. Kretchmer, and D. Walker, IEEE Electron Device Lett. 23 535 (2002).
Ch7:
[1] Yukio NARUKAWA, Masahiko SANO, Masatsugu ICHIKAWA, Shunsuke MINATO, Takahiko SAKAMOTO, Takao YAMADA, and Takashi MUKAI, Japanese Journal of Applied Physics, 46, L963–L965 (2007).
[2] Ansgar Laubsch, Matthias Sabathil, Johannes Baur, Matthias Peter, and Berthold Hahn, IEEE TRANSACTIONS ON ELECTRON DEVICES, 57, 1 (2010).
[3] Johannes Baur, Frank Baumann, Matthias Peter1, Karl Engl, Ulrich Zehnder, Juergen Off, Volker Kuemmler, Markus Kirsch, Joerg Strauss, Ralph Wirth, Klaus Streubel, and Berthold Hahn, Volker Kuemmler, Markus Kirsch, Joerg Strauss, Ralph Wirth, Klaus Streubel, and Berthold Hahn, Phys. Status Solidi C, 6, S905-S908 (2009).