Please use this identifier to cite or link to this item:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/50269Full metadata record
| ???org.dspace.app.webui.jsptag.ItemTag.dcfield??? | Value | Language |
|---|---|---|
| dc.contributor.advisor | 吳育任 | |
| dc.contributor.author | Chen-Kuo Wu | en |
| dc.contributor.author | 吳鎮國 | zh_TW |
| dc.date.accessioned | 2021-06-15T12:34:30Z | - |
| dc.date.available | 2016-08-24 | |
| dc.date.copyright | 2016-08-24 | |
| dc.date.issued | 2015 | |
| dc.date.submitted | 2016-08-01 | |
| dc.identifier.citation | [1] D. A. Browne, B. Mazumder, Y.-R. Wu, and J. S. Speck, “Electron
transport in unipolar InGaN/GaN multiple quantum well structures grown by NH3 molecular beam epitaxy,” Journal of Applied Physics, vol. 117, no. 13, p. 185703, 2015. [2] N. K. van der Laak, R. A. Oliver, M. J. Kappers, and C. J. Humphreys, “Role of gross well-width fluctuations in bright, green-emitting single InGaN/GaN quantum well structures,” Applied physics letters, vol. 90, no. 12, pp. 121911–121911, 2007. [3] N. Van der Laak, R. Oliver, M. Kappers, and C. Humphreys, “Characterization of InGaN quantum wells with gross fluctuations in width,” Journal of applied physics, vol. 102, no. 1, p. 013513, 2007. [4] A. Hangleiter, F. Hitzel, C. Netzel, D. Fuhrmann, U. Rossow, G. Ade, and P. Hinze, “Suppression of nonradiative recombination by V-shaped pits in GaInN/GaN quantum wells produces a large increase in the light emission efficiency,” Physical review letters, vol. 95, no. 12, p. 127402, 2005. [5] S. Tomiya, Y. Kanitani, S. Tanaka, T. Ohkubo, and K. Hono, “Atomic scale characterization of GaInN/GaN multiple quantum wells in V-shaped pits,” Applied Physics Letters, vol. 98, no. 18, p. 181904, 2011. [6] D. A. Browne, B. Mazumder, Y.-R. Wu, and J. S. Speck, “Investigation of electron transport through InGaN quantum well structures,” in 14th Electronic Materials Conference, Santa Barbara, USA, June 25-27, 2014. [7] Y.-Y. Lin, R. Chuang, S.-J. Chang, S. Li, Z.-Y. Jiao, T. Ko, S. Hon, and C. Liu, “GaN-based LEDs with a chirped multiquantum barrier structure,” IEEE Photonics Technology Letters, vol. 24, pp. 1600–1602, Sept 2012. [8] J. Piprek and Z. M. Simon Li, “Origin of InGaN lightemitting diode efficiency improvements using chirped AlGaN multi-quantum barriers,” Applied Physics Letters, vol. 102, no. 2, p. 023510, 2013. [9] C.-H. Lu, Y.-C. Li, Y.-H. Chen, S.-C. Tsai, Y.-L. Lai, Y.-L. Li, and C.-P. Liu, “Output power enhancement of InGaN/GaN based green light-emitting diodes with high-density ultra-small In-richquantum dots,” Journal of Alloys and Compounds, vol. 555, pp. 250–254, 2013. [10] O. Ambacher, J. Majewski, C. Miskys, A. Link, M. Hermann, M. Eickhoff, M. Stuzmann, F. Bernardini, V. Fiorentini, V. Tilak, B. Schaff, and L. F. Eastman, “Pyroelectric properties of Al(In)GaN/GaN hetero- and quantum well structures,” J. Phys.: Condens. Matter, vol. 14, pp. 3399–3434, 2002. [11] A. E. Romanov, T. J. Baker, S. Nakamura, J. S. Speck, and E. U. Group, “Strain-induced polarization in wurtzite III-nitride semipolar layers,” Journal of Applied Physics, vol. 100, no. 2, p. 023522, 2006. [12] C. Weisbuch, M. Piccardo, L. Martinelli, J. Iveland, J. Peretti, and J. S. Speck, “The efficiency challenge of nitride light-emitting diodes for lighting,” physica status solidi (a), 2015. [13] K. T. Delaney, P. Rinke, and C. G. Van de Walle, “Auger recombination rates in nitrides from first principles,” Applied Physics Letters, vol. 94, no. 19, p. 191109, 2009. [14] E. Kioupakis, P. Rinke, K. T. Delaney, and C. G. Van de Walle, “Indirect Auger recombination as a cause of efficiency droop innitride light-emitting diodes,” Applied Physics Letters, vol. 98, no. 16, p. 161107, 2011. [15] J. Iveland, L. Martinelli, J. Peretti, J. S. Speck, and C. Weisbuch, “Direct measurement of Auger electrons emitted from a semiconductor light-emitting diode under electrical injection: Identification of the dominant mechanism for efficiency droop,” Phys. Rev. Lett., vol. 110, p. 177406, Apr 2013. [16] M. Binder, A. Nirschl, R. Zeisel, T. Hager, H.-J. Lugauer, M. Sabathil, D. Bougeard, J. Wagner, and B. Galler, “Identification of nnp and npp auger recombination as significant contributor to the efficiency droop in (GaIn) N quantum wells by visualization of hot carriers in photoluminescence,” Applied Physics Letters, vol. 103, no. 7, p. 071108, 2013. [17] J.-H. Ryou, P. D. Yoder, J. Liu, Z. Lochner, H. Kim, S. Choi, H. J. Kim, and R. D. Dupuis, “Control of quantum-confined stark effect in InGaN-based quantum wells,” Selected Topics in Quantum Electronics, IEEE Journal of, vol. 15, no. 4, pp. 1080–1091, 2009. [18] H.-Y. Ryu, D.-S. Shin, and J.-I. Shim, “Analysis of efficiency droop in nitride light-emitting diodes by the reduced effective vol-ume of InGaN active material,” Applied Physics Letters, vol. 100, no. 13, p. 131109, 2012. [19] J.Wang, L.Wang, W. Zhao, Z. Hao, and Y. Luo, “Understanding efficiency droop effect in InGaN/GaN multiple-quantum-well blue light-emitting diodes with different degree of carrier localization,” Applied Physics Letters, vol. 97, no. 20, p. 201112, 2010. [20] S. Hammersley, D. Watson-Parris, P. Dawson, M. Godfrey, T. Badcock, M. Kappers, C. McAleese, R. Oliver, and C. Humphreys, “The consequences of high injected carrier densities on carrier localization and efficiency droop in InGaN/GaN quantum well structures,” Journal of Applied Physics, vol. 111, no. 8, p. 083512, 2012. [21] C. kang Li, M. Rosmeulen, E. Simoen, and Y.-R. Wu, “Study on the optimization for current spreading effect of lateral GaN/InGaN LEDs,” IEEE Transactions on Electron Devices, vol. 61, pp. 511–517, Feb 2014. [22] V. Malyutenko, S. Bolgov, and A. Podoltsev, “Current crowding effect on the ideality factor and efficiency droop in blue lateral In-GaN/GaN light emitting diodes,” Applied Physics Letters, vol. 97, no. 25, p. 251110, 2010. [23] J. Hader, J. Moloney, and S. Koch, “Density-activated defect recombination as a possible explanation for the efficiency droop in GaN-based diodes,” in SPIE OPTO, pp. 79540H–79540H, International Society for Optics and Photonics, 2011. [24] X. Ni, X. Li, J. Lee, S. Liu, V. Avrutin, A. Matulionis, U. Ozgur, and H. Morkoc, “Pivotal role of ballistic and quasi-ballistic electrons on LED efficiency,” Superlattices and Microstructures, vol. 48, pp. 133–153, 2010. [25] F. Akyol, D. N. Nath, S. Krishnamoorthy, P. S. Park, and S. Rajan, “Suppression of electron overflow and efficiency droop in Npolar GaN green light emitting diodes,” Applied Physics Letters, vol. 100, no. 11, p. 111118, 2012. [26] K. J. Vampola, M. Iza, S. Keller, S. P. DenBaars, and S. Nakamura, “Measurement of electron overflow in 450 nm InGaN lightemitting diode structures,” Applied Physics Letters, vol. 94, no. 6, p. 061116, 2009. [27] J. Xie, X. Ni, Q. Fan, R. Shimada, ぴUmit ぴOzgぴur, and H. Morko¸c, “On the efficiency droop in InGaN multiple quantum well blue light emitting diodes and its reduction with p-doped quantum well barriers,” Applied Physics Letters, vol. 93, no. 12, p. 121107, 2008. [28] J. P. Liu, J.-H. Ryou, R. D. Dupuis, J. Han, G. D. Shen, and H. B. Wang, “Barrier effect on hole transport and carrier distribution in InGaN/GaN multiple quantum well visible light-emitting diodes,” Applied Physics Letters, vol. 93, no. 2, p. 021102, 2008. [29] C. Wang, S. Chang, P. Ku, J. Li, Y. Lan, C. Lin, H. Yang, H. Kuo, T. Lu, S. Wang, et al., “Hole transport improvement in InGaN/GaN light-emitting diodes by graded-composition multiple quantum barriers,” Applied Physics Letters, vol. 99, no. 17, p. 171106, 2011. [30] 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,” Applied Physics Letters, vol. 92, no. 5, p. 053502, 2008. [31] D. S. Meyaard, G.-B. Lin, Q. Shan, J. Cho, E. F. Schubert, H. Shim, M.-H. Kim, and C. Sone, “Asymmetry of carrier transport leading to efficiency droop in GaInN based light-emitting diodes,” Applied Physics Letters, vol. 99, no. 25, p. 251115, 2011. [32] N. Bochkareva, V. Voronenkov, R. Gorbunov, A. Zubrilov, Y. S. Lelikov, P. Latyshev, Y. Rebane, A. Tsyuk, and Y. Shreter, “Defect-related tunneling mechanism of efficiency droop in IIInitride light-emitting diodes,” Applied Physics Letters, vol. 96, no. 13, p. 133502, 2010. [33] B. Monemar and B. Sernelius, “Defect related issues in the current roll-off in InGaN based light emitting diodes,” Applied Physics Letters, vol. 91, no. 18, p. 181103, 2007. [34] J. Piprek and S. Li, “Electron leakage effects on GaN-based lightemitting diodes,” Optical and Quantum Electronics, vol. 42, no. 2, pp. 89–95, 2010. [35] Y.-K. Kuo, M.-C. Tsai, S.-H. Yen, T.-C. Hsu, and Y.-J. Shen, “Effect of p-type last barrier on efficiency droop of blue InGaN lightemitting diodes,” IEEE Journal of Quantum Electronics, vol. 46, pp. 1214–1220, Aug 2010. 36] S. Chichibu, K. Wada, and S. Nakamura, “Spatially resolved cathodoluminescence spectra of InGaN quantum wells,” Applied physics letters, vol. 71, no. 16, pp. 2346–2348, 1997. [37] N. K. van der Laak, R. A. Oliver, M. J. Kappers, and C. J. Humphreys, “Role of gross well-width fluctuations in bright, green-emitting single InGaN/GaN quantum well structures,” Applied physics letters, vol. 90, no. 12, pp. 121911–121911, 2007. [38] T.-J. Yang, R. Shivaraman, J. S. Speck, and Y.-R. Wu, “The influence of random indium alloy fluctuations in indium gallium nitride quantum wells on the device behavior,” Journal of Applied Physics, vol. 116, no. 11, p. 113104, 2014. [39] C.-K. Li, H.-C. Yang, T.-C. Hsu, Y.-J. Shen, A.-S. Liu, and Y.- R. Wu, “Three dimensional numerical study on the efficiency of a core-shell InGaN/GaN multiple quantum well nanowire lightemitting diodes,” Journal of Applied Physics, vol. 113, no. 18, p. 183104, 2013. [40] C.-K. Li, P.-C. Yeh, J.-W. Yu, L.-H. Peng, and Y.-R. Wu, “Scaling performance of Ga2O3/GaN nanowire field effect transistor,” Journal of Applied Physics, vol. 114, no. 16, p. 163706, 2013. [41] C.-K. Wu, C.-K. Li, and Y.-R. Wu, “Percolation transport study in nitride based LED by considering the random alloy fluctuation,” Journal of Computational Electronics, vol. 14, no. 2, pp. 416–424, 2015. [42] Y.-R. Wu, R. Shivaraman, K.-C. Wang, and J. S. Speck, “Analyzing the physical properties of InGaN multiple quantum well light emitting diodes from nano scale structure,” Applied Physics Letters, vol. 101, no. 8, p. 083505, 2012. [43] J. R. Riley, T. Detchprohm, C. Wetzel, and L. J. Lauhon, “On the reliable analysis of indium mole fraction within InxGa1−xN quantum wells using atom probe tomography,” Applied Physics Letters, vol. 104, no. 15, p. 152102, 2014. [44] R. Shivaraman, Y. Kawaguchi, S. Tanaka, S. DenBaars, S. Nakamura, and J. Speck, “Comparative analysis of 2021 and 2021 semipolar GaN light emitting diodes using atom probe tomography,” Applied Physics Letters, vol. 102, no. 25, pp. 251104–4, 2013. [45] S. E. Bennett, D. W. Saxey, M. J. Kappers, J. S. Barnard, C. J. Humphreys, G. D. Smith, and R. A. Oliver, “Atom probe to-mography assessment of the impact of electron beam exposure on InxGa1−xN/GaN quantum wells,” Applied Physics Letters, vol. 99, no. 2, p. 021906, 2011. [46] M. J. Galtrey, R. A. Oliver, M. J. Kappers, C. J. Humphreys, P. H. Clifton, D. Larson, D. W. Saxey, and A. Cerezo, “Threedimensional atom probe analysis of green- and blue-emitting InxGa1−xN/GaN multiple quantum well structures,” Journal of Applied Physics, vol. 104, no. 1, p. 013524, 2008. [47] M. J. Galtrey, R. A. Oliver, M. J. Kappers, C. J. Humphreys, D. J. Stokes, P. H. Clifton, and A. Cerezo, “Three-dimensional atom probe studies of an InxGa1−xN/GaN multiple quantum well structure: Assessment of possible indium clustering,” Applied Physics Letters, vol. 90, no. 6, 2007. [48] D. Watson-Parris, M. J. Godfrey, P. Dawson, R. A. Oliver, M. J. Galtrey, M. J. Kappers, and C. J. Humphreys, “Carrier localization mechanisms in InxGa1−xN/GaN quantum wells,” Phys. Rev. B, vol. 83, p. 115321, Mar 2011. [49] J. Speck, “Unraveling the efficiency limits of GaN-based emitters and the surprising connection to electron devices,” in ISSLED,2014. [50] W. Lv, L. Wang, L. Wang, Y. Xing, D. Yang, Z. Hao, and Y. Luo, “InGaN quantum dot green light-emitting diodes with negligible blue shift of electroluminescence peak wavelength,” Applied Physics Express, vol. 7, no. 2, p. 025203, 2014. [51] W. Lv, L. Wang, J. Wang, Y. Xing, J. Zheng, D. Yang, Z. Hao, and Y. Luo, “Green and red light-emitting diodes based on multilayer InGaN/GaN dots grown by growth interruption method,” Japanese Journal of Applied Physics, vol. 52, no. 8S, p. 08JG13, 2013. [52] Y. Chen, T. Takeuchi, H. Amano, I. Akasaki, N. Yamada, Y. Kaneko, and S. Wang, “Pit formation in GaInN quantum wells,” Applied physics letters, vol. 72, no. 6, pp. 710–712, 1998. [53] C.-Y. Chang, H. Li, Y.-T. Shih, and T.-C. Lu, “Manipulation of nanoscale v-pits to optimize internal quantum efficiency of InGaN multiple quantum wells,” Applied Physics Letters, vol. 106, no. 9, p. 091104, 2015. [54] N. Okada, H. Kashihara, K. Sugimoto, Y. Yamada, and K. Tadatomo, “Controlling potential barrier height by changing V-shaped pit size and the effect on optical and electrical properties for InGaN/GaN based light-emitting diodes,” Journal of Applied Physics, vol. 117, no. 2, p. 025708, 2015. [55] J. Kim, J. Kim, Y. Tak, S. Chae, J.-Y. Kim, and Y. Park, “Effect of V-shaped pit size on the reverse leakage current of InGaN/GaN light-emitting diodes,” Electron Device Letters, IEEE, vol. 34, no. 11, pp. 1409–1411, 2013. [56] Z. Quan, L. Wang, C. Zheng, J. Liu, and F. Jiang, “Roles of V-shaped pits on the improvement of quantum efficiency in In- GaN/GaN multiple quantum well light-emitting diodes,” Journal of Applied Physics, vol. 116, no. 18, p. 183107, 2014. [57] J. Kim, Y.-H. Cho, D.-S. Ko, X.-S. Li, J.-Y. Won, E. Lee, S.-H. Park, J.-Y. Kim, and S. Kim, “Influence of V-pits on the efficiency droop in InGaN/GaN quantum wells,” Optics express, vol. 22, no. 103, pp. A857–A866, 2014. [58] C. Geuzaine and J.-F. Remacle, “Gmsh: A 3-D finite element mesh generator with built-in pre- and post-processing facilities,” Int. J. Numer. Meth. Engng., vol. 79, p. 1309V1331, 2009. [59] M. Sabathil, A. Laubsch, and N. Linder, “Self-consistent modeling of resonant PL in InGaN SQW LED-structure,” Proc. SPIE, vol. 6486, pp. 64860V–9, 2007. [60] I. Vurgaftman, J. R. Meyer, and L. R. Ram-Mohan, “Band parameters for III–V compound semiconductors and their alloys,” Journal of Applied Physics, vol. 89, no. 11, pp. 5815–5875, 2001. [61] S. L. Chuang and C. S. Chang, “k·p method for strained wurtzite semiconductors,” Phys. Rev. B, vol. 54, pp. 2491–2504, Jul 1996. [62] J. Wu, “When group-III nitrides go infrared: New properties and perspectives,” Journal of Applied Physics, vol. 106, no. 1, p. 011101, 2009. [63] C.-C. Hsu, C.-K. Wu, C.-K. Li, C.-H. Wu, and Y.-R. Wu, “Analyzing the strain distribution in the InGaN quantum well with random indium alloy fluctuation by 3D finite element strain analysis model,” in Compound Semiconductor, 2015. [64] Y.-R. Wu, Y.-Y. Lin, H.-H. Huang, and J. Singh, “Electronic and optical properties of InGaN quantum dot based light emitters for solid state lighting,” Journal of applied physics, vol. 105, no. 1, p. 013117, 2009. [65] C.-C. Hsu, 3D Finite Element Strain Analysis of InGaN Quantum Well Structures. National Taiwan University Graduate Institute of Electro-Optical Engineering, 2015. [66] D. N. Nath, Z. C. Yang, C.-Y. Lee, P. S. Park, Y.-R. Wu, and S. Rajan, “Unipolar vertical transport in GaN/AlGaN/GaN heterostructures,” Applied Physics Letters, vol. 103, no. 2, p. 022102, 2013. [67] S. Tomiya, Y. Kanitani, S. Tanaka, T. Ohkubo, and K. Hono, “Atomic scale characterization of GaInN/GaN multiple quantum wells in V-shaped pits,” Applied Physics Letters, vol. 98, no. 18, p. 181904, 2011. [68] X. Wu, J. Liu, Z. Quan, C. Xiong, C. Zheng, J. Zhang, Q. Mao, and F. Jiang, “Electroluminescence from the sidewall quantum wells in the V-shaped pits of InGaN light emitting diodes,” Applied Physics Letters, vol. 104, no. 22, p. 221101, 2014. | |
| dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/50269 | - |
| dc.description.abstract | 根據實驗結果顯示，有許多奈米尺度的結構擾動存在於三元化合
物氮化銦鎵量子井以及氮化鋁鎵電子阻擋層中。而這寫結構擾動的 尺度從個位數奈米尺度(隨機合金分布擾動)、數十奈米尺度(不完整 量子井結構)、或數百奈米尺度(V型缺陷)。而這些奈米尺度的結構 擾動將會顯著地影響載子傳輸以及輻射發光複合。因此，我們有必 要使用一個適當的模型去分析其影響。本篇論文中，我們將使用我 們實驗室開發的三維有限元素帕松與漂移-擴散模型去分析這些主 題。首先，為了瞭解極化位勢壘如何影響氮化鎵元件系統中的載子 傳輸現象，我們將考慮隨機合金分佈擾動去分析n-i-n氮化銦鎵量子 井系統、n-i-n鋁化銦鎵量子位勢壘系統以及使用不同種電子阻擋層 的發光二極體去分析結構中的傳導帶位能分佈、電流-電壓表現以及 內部量子效應。結果顯示考慮隨機合金分佈擾動可以更能擬合實驗 電流-電壓曲線，也顯示在較薄的磊晶層中，隨機合金分佈擾動將會 更顯著地影響載子局域以及傳輸。此外，我們使用二維以及三維的 模型去分析常存於綠光發光二極體中量子井不完整的結構。結果顯 示，考慮了不完整的量子井結構的計算結果更能接近實際元件的表 現。有了較能適當描述綠光發光二極體電性的模型，我們更可進一 步分析綠光發光二極體中其他物理行為與表現。在最後一章，我們將探討考慮V型缺陷在氮化銦鎵藍光發光二極體中的物理特性。我 們將使用三維應力-應變計算程式以及載子傳輸模型去分析結構中的 電流走向，並更進一步討論對量子效率以及電流-電壓的表現。而模 擬結果顯示，在V型缺陷濃度較低的側壁量子井會提供較小的極化 位勢壘以及較淺的位能井。因此V型缺陷可以幫助載子注入，並幫 助載子注入平面的主動區，使得載子可以避免被非輻射複合中心所 影響。而相較於傳統量子井發光二極體結構，V型缺陷能使載子較 能平均的分佈在平面量子井中。此外，我們更進一步地結合隨機合 金分佈擾動模型以及V型缺陷結構，去探討V型缺陷對接通電壓和量 子效率表現的影響。V型缺陷的結構將會使存有V型缺陷的發光二極 體相較於沒有存有V型缺陷的元件，能提供更多載子路徑且幫助載 子的注入，使得含有V型缺陷的結構有著更小的接通電壓以及更高 的內部量子效率。此外，考慮合金分佈不均的發光二極體以及V型 缺陷模型的接通電壓計算結果更能解釋實驗觀察的接通電壓。本章 的最後一部份，我們將探討不同大小的V型缺陷對元件的影響。不 同大小的V型缺陷元件受陷阱所致的非輻射複合中心影響程度不同 以及有著不同大小的量子井發光區域，將會對有著不一樣的內部量 子效率的表現。V型缺陷的特殊結構不只能提供額外的電洞流的路 徑也能防止載子在線差排缺線中非輻射複合。 關鍵字: 藍綠色發光二極體, 合金含量波動, 非完整量子井結構, V型缺陷, 氮化鎵, 氮化銦鎵, 氮化鋁鎵 | zh_TW |
| dc.description.abstract | The experimental results show that there are nano-scale composition
fluctuations existing in the ternary alloy of InGaN quantum wells (QWs) and AlGaN electron blocking layer (EBL). The scales of fluctuations are ranging from the units nanometer scale (random alloy fluctuations), tens nanometer scale (imperfect QWs), or hundreds nanometer scale (V-pits). The existence of nano-scale fluctuations will affect the carrier transport and radiative recombination strongly. Therefore, we need to develop a suitable model to analyze these effects. In this thesis, we applied our inhouse 3D FEM Poisson and drift-diffusion solver to analyze these problems. In the beginning, to understand how the piezoelectric barrier influence the carrier injection in GaN device system, we took the n-i-n InGaN system, n-i-n AlGaN quantum barrier (QB) and light emitting diodes (LEDs) with different EBLs to analyze the conduction band potential distribution, I-V performance and internal quantum efficiency (IQE) by considering the random alloy fluctuation. The results show a better fit in I-V curve and reveal that the random alloy fluctuation will affect the carrier confinement and transport significantly, epecially in a thinner epi-layer case. Besides, the imperfect QWs which commonly exist in the green emission LEDs are modeled by our 2D and 3D simulation programs. According to the calculated results, we can more approach the experimental IV performance by considering imperfect QW structures. With properly modeling the electric property, this model could provide a basis for further modeling other physical properties in green LEDs. In the last part, a V-pit embedded inside the blue InGaN LED was studied. A 3D strain-stress sovler and carrier transport model were employed to study the current path, where the quantum efficiency and turn-on voltage will be discussed. Our calculated results show that the shallow sidewall QWs will provide extra hole current flow paths, and make the carrier distribution more uniform along lateral QWs than traditional planar MQWs, which have high piezoelectric barriers make carriers hard to flow through. In addition, the random alloy fluctuation model is applied in the V-pit structure to compare the turn-on voltage and quantum efficiency with planar structure LEDs. The sidewall structure will provide more percolation paths for carriers and improve the carrier injection so that the V-pit LEDs perform smaller turn-on voltage and higher simulated IQE value than planar MQW LEDs. Moreover, the simulated turn-on voltage of the V-pit LED with the random alloy fluctuation model can be pushed earlier to appropriately explain the experimental data. In the last part of this section, the carrier transport by considering the size effect is studied. The variation of the internal quantum efficiency (IQE) for different V-pit sizes is due to the trap-assisted nonradiative recombination and QW areas. The V-pit structure would not only enhance the hole percolation length but act as a potential barrier to prevent carriers from nonradiatively recombining in threading dislocations (TDs). Keywords: blue-green light emitting diode, alloy fluctuation, imperfect quantum well structure, V-shaped pit, GaN, InGaN, AlGaN | en |
| dc.description.provenance | Made available in DSpace on 2021-06-15T12:34:30Z (GMT). No. of bitstreams: 1 ntu-104-R02941091-1.pdf: 20088453 bytes, checksum: fea1f93ba444ac1b82488eb05e62a87a (MD5) Previous issue date: 2015 | en |
| dc.description.tableofcontents | 目錄
口試委員會審定書. . . . . . . . . . . . . . . . . . . . . . . . . i 誌謝. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii 中文摘要. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv 英文摘要. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii 目錄. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x 圖目錄. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii 表目錄. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxii 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Random Alloy Fluctuation . . . . . . . . . . . . . . . . 5 1.3 Imperfect Quantum Well . . . . . . . . . . . . . . . . . 7 1.4 V-Shaped Pit in GaN Based LEDs . . . . . . . . . . . 10 1.5 Thesis Overview . . . . . . . . . . . . . . . . . . . . . . 14 2 SimulationMethod . . . . . . . . . . . . . . . . . . . . . . . 17 2.1 Computation Algorithm . . . . . . . . . . . . . . . . . 17 2.2 Generation of the Random Alloy Composition Map . . 19 2.3 3D FEM Elastic Strain Solver . . . . . . . . . . . . . . 23 2.4 3-D Poisson Drift-Diffusion Self-Consistent Solver . . . 26 3 Percolation Transport in the Random Alloy System . . . . . 28 3.1 Electron Transport in n-GaN/ i-InGaN / n-GaN Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 3.2 Electron Transport in n-GaN/ i-AlGaN / n-GaN Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 3.3 3D Vertical Transport in LED Structures with Different EBLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 4 The Influence of Imperfect QWs in the Carrier Transport Simulation of Green LEDs . . . . . . . . . . . . . . . . . . . 55 4.1 2D Examination of Green Emission bt the Imperfect QWs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 4.2 3D Examination of Green Emission Imperfect QWs . . 64 5 3D Carrier Transport Study the Influence of V-shape Pits in Light Emitting Diodes . . . . . . . . . . . . . . . . . . . . . 68 5.1 The Electric and Optical Property of V-shaped Pits in LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 5.2 Geometric Diameter study of V-shaped Pits to the Carrier Injection . . . . . . . . . . . . . . . . . . . . . . . 77 6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 | |
| dc.language.iso | en | |
| dc.subject | 氮化鋁鎵 | zh_TW |
| dc.subject | 藍綠色發光二極體 | zh_TW |
| dc.subject | 合金含量波動 | zh_TW |
| dc.subject | 非完整量子井結構 | zh_TW |
| dc.subject | V型缺陷 | zh_TW |
| dc.subject | 氮化鎵 | zh_TW |
| dc.subject | 氮化銦鎵 | zh_TW |
| dc.subject | 藍綠色發光二極體 | zh_TW |
| dc.subject | 合金含量波動 | zh_TW |
| dc.subject | 非完整量子井結構 | zh_TW |
| dc.subject | V型缺陷 | zh_TW |
| dc.subject | 氮化鎵 | zh_TW |
| dc.subject | 氮化銦鎵 | zh_TW |
| dc.subject | 氮化鋁鎵 | zh_TW |
| dc.subject | V-shaped pit | en |
| dc.subject | blue-green light emitting diode | en |
| dc.subject | AlGaN | en |
| dc.subject | InGaN | en |
| dc.subject | GaN | en |
| dc.subject | blue-green light emitting diode | en |
| dc.subject | alloy fluctuation | en |
| dc.subject | imperfect quantum well structure | en |
| dc.subject | V-shaped pit | en |
| dc.subject | GaN | en |
| dc.subject | InGaN | en |
| dc.subject | AlGaN | en |
| dc.subject | alloy fluctuation | en |
| dc.subject | imperfect quantum well structure | en |
| dc.title | 三維數值模擬探討發光二極體中考慮奈米微結構的載子傳輸研究 | zh_TW |
| dc.title | 3D Numerical Carrier Transport Study by Considering Nano-Scale Structures in LEDs | en |
| dc.type | Thesis | |
| dc.date.schoolyear | 104-2 | |
| dc.description.degree | 碩士 | |
| dc.contributor.oralexamcommittee | 賴韋志,張允崇,盧廷昌 | |
| dc.subject.keyword | 藍綠色發光二極體,合金含量波動,非完整量子井結構,V型缺陷,氮化鎵,氮化銦鎵,氮化鋁鎵, | zh_TW |
| dc.subject.keyword | blue-green light emitting diode,alloy fluctuation,imperfect quantum well structure,V-shaped pit,GaN,InGaN,AlGaN, | en |
| dc.relation.page | 103 | |
| dc.identifier.doi | 10.6342/NTU201601533 | |
| dc.rights.note | 有償授權 | |
| dc.date.accepted | 2016-08-02 | |
| dc.contributor.author-college | 電機資訊學院 | zh_TW |
| dc.contributor.author-dept | 光電工程學研究所 | zh_TW |
| Appears in Collections: | 光電工程學研究所 | |
Files in This Item:
| File | Size | Format | |
|---|---|---|---|
| ntu-104-1.pdf Restricted Access | 19.62 MB | Adobe PDF |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.