本研究利用量子點材料搭配微小化(30 m30 m)氮化鎵藍光發光二極體，製作全彩微小化發光二極體陣列。首先製作微小化發光二極體陣列，並利用黑色矩陣光阻製作隔光結構以提升元件之對比度，同時結合工業技術研究院支援之量子點噴塗技術，將紅色量子點及綠色量子點噴塗於微小化藍光發光二極體陣列上。為進一步提升光色轉換之效率，本研究於元件結構部分進行改善，首先於微小化藍光發光二極體陣列基板的底部下方製作混合式布拉格反射鏡，將向基板輻射的藍光反射回正面以多次激發量子點;另外，在微小化藍光發光二極體陣列的頂部量子點上方製作分佈式布拉格反射鏡，將未完全被量子點所吸收之藍光再次反射回元件中，使藍光可以再次激發量子點，除了可提升光色轉換的效率之外，亦可達到紅色及綠色的光色純度的目的。本研究之全彩微小化發光二極體其紅光與綠光CIE色度座標分別位於(0.587,0.267)及(0.293,0.581)，而紅光及綠光之光色轉換效率分別為24.1%及23.3%。

In this study, the gallium nitride (GaN)-based blue light-emitting diode (LED) and quantum dots were used to fabricate the full color micro LED arrays (30 m30 m). In the fabrication of micro LED arrays, the black matrix photoresist was used to produce the light blocking structure, which could improve the pixel contrast ratio. In fabrication of color transformation layer, the red quantum dots and green quantum dots were sprayed on the surface of the micro light-emitting diode arrays using the spray technique provided by the Industrial Technology Research Institute. To further enhance the color conversion efficiency, the hybrid Bragg reflector was fabricated at the substrate bottom for the LED arrays to reflect the blue light that emitted to the substrate. In addition, the distributed Bragg reflector was fabricated on the top of the LED arrays to reflect the blue light wasn’t absorbed by the quantum dots back to the device. Consequently, the quantum dots can be excited by the blue light more times to enhance the color transform efficiency and the red and green light color purity. Finally, the experimental results demonstrated that the CIE chromaticity coordinate of the red and green LED in full color micro LED arrays were located at (0.587,0.267) and (0.293,0.581), and the conversion efficiency of red light and green light in full color micro LED arrays were 24.1% and 23.3%.

[1] Y. C. Chang, J. K. Liou, and W. C. Liu,“Improved light extraction efficiency of a high-power GaN-based light-emitting diode with a three-dimensional-photonic crystal (3-D-PhC) backside reflector”, IEEE Electron Device Letters, vol. 34, p. 777, 2013.
[2] Y. L. Chou, R. M. Lin, M. H. Tung, C. H. Tsai, J. C. Li, I. Kuo, and M. C. Wu,“Improvement of surface emission for GaN-based light-emitting diodes with a metal-via-hole structure embedded in a reflector”, IEEE Photonics Technology Letters, vol. 23, p. 393, 2011.
[3] E. J. Koerperick, J. T. Olesberg, J. L. Hicks, J. P. Prineas, and T. F. Boggess,“High-power MWIR cascaded InAs–GaSb superlattice LEDs”, IEEE Journal of Quantum Electronics, vol. 45, p. 849, 2009.
[4] C. T. Lee, U. Z. Yang, C. S. Lee, and P. S. Chen,“White light emission of monolithic carbon-implanted InGaN-GaN light-emitting diodes”, IEEE Photonics Technology Letters, vol. 18, p. 2029, 2006.
[5] J. Kwak, W. K. Bae, D. Lee, I. Park, J. Lim, M. Park, H. Cho, H. Woo, D. Y. Yoon, and K. Char,“Bright and efficient full-color colloidal quantum dot light-emitting diodes using an inverted device structure”, Nano Letters, vol. 12, p. 2362, 2012.
[6] Y. Yang, Y. Zheng, W. Cao, A. Titov, J. Hyvonen, J. R. Manders, J. Xue, P. H. Holloway, and L. Qian,“High-efficiency light-emitting devices based on quantum dots with tailored nanostructures”, Nature Photonics, vol. 9, p. 259, 2015.
[7] G. Fasol and S. Nakamura, “The blue laser diode: GaN based blue light emitters and lasers”, Springer, Berlin. 1997
[8] Y. J. Lin, Y. Zhang, J. Zhao, P. F. Gu, K. Bi, Q. R. Zhang, H. R. Chu, T. Q. Zhang, T. Cui, Y. D. Wang, J. Zhao, and W. W. Yu,“White-light-emitting diodes using GaN-excited CdSe/CdS/ZnS quantum dots”, Particuology, vol. 15, p. 90, 2014.
[9] A. Zukauskas, F. Ivanauskas, R. Vaicekauskas, M. S. Shur, and R. Gaska,“Optimization of multichip white solid state lighting source with four or more LEDs”, Proceedings of SPIE, vol. 4445, p. 148, 2001.
[10] Y. Shimizu, K. Sakano, Y. Noguchi, and T. Moriguchi, “Light emitting device having a nitride compound semiconductor and a phosphor containing a garnet fluorescent material”, U.S. Patent No 5998925. 1999
[11] S. Nakamura, T. Mukai, and M. Senoh,“Candela-class high-brightness InGaN/AlGaN double-heterostructure blue-light-emitting diodes”, Applied Physics Letters, vol. 64, p. 1687, 1994.
[12] S. Fujita, A. Sakamoto, and S. Tanabe,“Luminescence characteristics of YAG glass–ceramic phosphor for white LED”, IEEE Journal of Selected Topics in Quantum Electronics, vol. 14, p. 1387, 2008.
[13] S.Nishiura, S. Tanabe, K. Fujioka, and Y. Fujimoto,“Properties of transparent Ce: YAG ceramic phosphors for white LED”, Optical Materials, vol. 33, p. 688, 2011.
[14] J. S. Kim, J. Y. Kang, P. E. Jeon, J. C. Chol, H. L. Park, and T. W. Kim,“White-light generation through ultraviolet-emitting diode and white-emitting phosphor”, Applied Physics Letters, vol. 85, p. 3696, 2004.
[15] J. K. Sheu, S. J. Chang, C. H. Kuo, Y. K. Su, L. W. Wu, Y. C. Lin, W. C. Lai, J. M. Tsai, G. C. Chi, and R. K. Wu,“White-light emission from near UV InGaN-GaN LED chip precoated with blue/green/red phosphors”, IEEE Photonics Technology Letters, vol. 15, p. 18, 2003.
[16] F. Iskandar, K. Okuyama, and F. G. Shi,“Stable photoluminescence of zinc oxide quantum dots in silica nanoparticles matrix prepared by the combined sol–gel and spray drying method”, Journal of Applied Physics, vol. 89, p. 6431, 2001.
[17] K. J. Chen, H. C. Chen, K. A. Tsai, C. C. Lin, H. H. Tsa, S. H. Chien, B. S. Cheng, Y. J. Hsu, M. H. Shih, and C. H. Tsai,“Resonant-enhanced full-color emission of quantum-dot-based display technology using a pulsed spray method”, Advanced Functional Materials, vol. 22, p. 5138, 2012.
[18] H. Song and S. Lee,“Photoluminescent (CdSe) ZnS quantum dot-polymethylmethacrylate polymer composite thin films in the visible spectral range”, Nanotechnology, vol. 18, p. 055402, 2007.
[19] H. W. Huang, C. H. Lin, C. C. Yu, B. D. Lee, H. C. Kuo, K. M. Leung, and S. C. Wang,“Investigation of InGaN/GaN power chip light emitting diodes with TiO2/SiO2 omnidirectional reflector”, Semiconductor Science and Technology, vol. 23, p. 125006, 2008.
[20] S. J. Chang, C. F. Shen, M. H. Hsieh, C. T. Kuo, T. K. Ko, W. S. Chen, and S. C. Shei,“Nitride-based LEDs with a hybrid Al mirror+TiO2/SiO2 DBR backside reflector”, Journal of Lightwave Technology, vol. 26, p. 3131, 2008.
[21] E. F. Schubert, T. Gessmann, and J. K. Kim“Light emitting diodes”. Wiley Online Library. 2005
[22] A. A. Bergh and P. J. Dean,“Light-emitting diodes”, Proceedings of the IEEE, vol. 60, p. 156, 1972.
[23] R. E. Bailey, A. M. Smith, and S. Nie,“Quantum dots in biology and medicine”, Physica E: Low-dimensional Systems and Nanostructures, vol. 25, p. 1, 2004.
[24] H. C. Liu, M. Gao, J. McCaffrey, Z. R. Wasilewski, and S. Fafard,“Quantum dot infrared photodetectors”, Applied Physics Letters, vol. 78, p. 79, 2001.
[25] X. Michalet, F. F. Pinaud, L. A. Bentolila, J. M. Tsay, S. Doose, J. J. Li, G. Sundaresan, A. M. Wu, S. S. Gambhir, and S. Weiss,“Quantum dots for live cells, in vivo imaging, and diagnostics”, Science, vol. 307, p. 538, 2005.
[26] M. Kroutvar, Y. Ducommun, D. Heiss, M. Bichler, D. Schuh, G. Abstreiter, and J. J. Finley,“Optically programmable electron spin memory using semiconductor quantum dots”, Nature, vol. 432, p. 81, 2004.
[27] A. P. Alivisatos,“Semiconductor clusters, nanocrystals, and quantum dots”, Science, vol. 271, p. 933, 1996.
[28] C. C. Lin and C. T. Lee,“Enhanced light extraction mechanism of GaN-based light-emitting diodes using top surface and side-wall nanorod arrays”, IEEE Photonics Technology Letters, vol. 22, p. 1132, 2010.
[29] D. H. Kim, C. O. Cho, Y. G. Roh, H. Joen, Y. S. Park, J. Cho, J. S. Im, C. Sone, Y. Park, W. J. Choi, and Q. H. Park,“Enhanced light extraction from GaN-based light-emitting diodes with holographically generated two-dimensional photonic crystal patterns”, Applied Physics Letters, vol. 87, p. 203508, 2005.
[30] M. Yamada, T. Mitani, Y. Narukawa, S. Shioji, I. Niki, S. Sonobe, K. Deguchi, M. Sano, and T. Mukai,“InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode”, Japanese Journal of Applied Physics, vol. 41, p. L1431, 2002.
[31] T. Fujii, Y. Gao, R. Sharma, E. L. Hu, S. P. DenBaars, and S. Nakamura,“Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening”, Applied Physics Letters, vol. 84, p. 855, 2004.
[32] Y. S. Zhao, D. L. Hibbard, H. P. Lee, K. Ma, W. So, and H. Liu,“Efficiency enhancement of InGaN/GaN light-emitting diodes with a back-surface distributed Bragg reflector”, Journal of Electronic Materials, vol. 32, p. 1523, 2003.
[33] C. H. Chen, S. J. Chang, Y. K. Su, G. C. Chi, J. K. Sheu, and J. F. Chen,“High-efficiency InGaN-GaN MQW green light-emitting diodes with CART and DBR structures”, IEEE Journal of Selected Topics in Quantum Electronics vol. 8, p. 284, 2002.
[34] N. M. Lin, S. C. Shei, and S. J. Chang,“Nitride-based LEDs with high-reflectance and wide-angle Ag mirro+SiO2/TiO2 DBR backside reflector”, Journal of Lightwave Technology, vol. 29, p. 1033, 2011.
[35] R. W. G. Hunt and M. R. Pointer“Measuring colour”. John Wiley & Sons. 2011
[36] B. O. Dabbousi, J. Rodriguez-Viejo, F. V. Mikulec, J. R. Heine, H. Mattoussi, R. Ober, K. F. Jensen, and M. G. Bawendi,“(CdSe) ZnS core-shell quantum dots: synthesis and characterization of a size series of highly luminescent nanocrystallites”, The Journal of Physical Chemistry B, vol. 101, p. 9463, 1997.
[37] W. Chung, K. Park, H. J. Yu, J. Kim, B. H. Chun, and S. H. Kim,“White emission using mixtures of CdSe quantum dots and PMMA as a phosphor”, Optical Materials, vol. 32, p. 515, 2010.
[38] H. S. Jang, Y. H. Won, and D. Y. Jeon,“Improvement of electroluminescent property of blue LED coated with highly luminescent yellow-emitting phosphors”, Applied Physics B, vol. 95, p. 715, 2009.
[39] H. Luo, J. K. Kim, E. F. Schubert, J. Cho, C. Sone, and Y. Park,“Analysis of high-power packages for phosphor-based white-light-emitting diodes”, Applied Physics Letters, vol. 86, p. 243505, 2005.
[40] S. Chanyawadee, P. G. Lagoudakis, R. T. Harley, M. D. B. Charlton, D. V. Talapin, H. W. Huang, and C. H. Lin,“Increased color-conversion efficiency in hybrid light-emitting diodes utilizing non-radiative energy transfer”, Advanced Materials, vol. 22, p. 602, 2010.