在本論文中，我們選用茚並茚(Dihydroindeno[2,1-a]indene)作為主體架構開發深藍色螢光客體材料，因其具有以下優點：(1)具有高螢光量子效率；(2)本身的剛性結構可提升材料的熱穩定性；(3)共軛鏈長度短可經由簡單的官能基修飾達到深藍光。我們設計合成出四種四苯基茚並茚(4PhDI)客體材料(圖1)，分別引入拉電子基團與推電子基團修飾，期望增加載子傳遞的平衡性，且進一步比較不同官能基性質對效率的影響。此一系列客體材料的熱裂解溫度皆大於400 oC，且於350 oC之前也未觀察到玻璃轉化溫度，證實茚並茚結構確實為材料帶來良好的熱穩定性。將此一系列客體材料摻雜於主體材料DMPPP後，以4PhDI-2CN為客體材料的元件擁有最佳的效率表現，其最大外部量子效率、發光效率分別為10.0%、7.9 cd/A，CIEx,y座標可達(0.15, 0.08)，且於高亮度下幾乎未出現效率滾降(roll-off)的現象，與近年來極飽和深藍光(Ultra-deep blue)的文獻相比其效率表現相當優異，由暫態電激發光實驗中發現此系列材料製成的元件有延遲螢光的現象，因此推測此系列材料能藉由三重態-三重態淬熄機制(Triplet-Triplet Annihilation, TTA)提升元件的效率，且於此系列材料引入拉電子基團有較好的TTA效應。
接著我們為了降低材料於昇華純化時的操作溫度，將四苯基茚並茚中的苯環替換成甲基，降低材料的分子量減少分子間作用力，我們合成出四種四甲基茚並茚(4MeDI)客體材料探討(圖1)，其中使用拉電子基團的4MeDI-3N與使用芳香環的4MeDI-Py光色相近，發現以4MeDI-3N為客體材料的元件有較佳的效率表現，其最大外部量子效率、發光效率分別為9.7%、12.6 cd/A，CIEx,y座標位於(0.14, 0.15)，而此差異與材料的螢光量子效率(ΦPL)有關，且於暫態電激發光實驗中4MeDI-3N的延遲螢光強度與4MeDI-Py相比明顯較強，而有較好的TTA效應。

Dihydroindeno[2,1-a]indene, a rigid structure containing a stilbene moiety, was selected as an emission core for the development of and study new materials that emit deep-blue light with high efficiency. Four fluorescent dopants based on the core 4PhDI derivatives (Figure 1), 4PhDI-2CN, 4PhDI-3N, 4PhDI-CN and 4PhDI-TPA have been synthesized. The materials were expected to facilitate the charge balance in the device by introducing electron-withdrawing group or electron-donating group. On the other hand, these compounds exhibit excellent thermal stability with decomposition temperature above 400 oC, and no glass transition temperature was observed in the range of 50 oC to 400 oC. Moreover, the device using DMPPP doped with 5% 4PhDI-2CN as an emitting layer shows a maximum external quantum efficiency (E.Q.E.) of 10.0% and the current efficiency (C.E.) of 7.9 cd/A with the CIE coordinates of (0.15, 0.08), which is close to (0.14, 0.08) in the National Television System Committee (NTSC) standard. Espeacially, the device exhibits low efficiency roll-off at the high luminance, and the outstanding performance of the device can be attributed to triplet-triplet annihilation (TTA) up-conversion mechanism.
Further, we have synthesized a series of deep-blue dopants with the new core 4MeDI (Figure 1). By decreasing the molecular weight of these materials, the purification by sublimation could be conducted at the appropriate temperature. In the case of 4MeDI-3N and 4MeDI-Py, which display the same color, the device using 4MeDI-3N as a dopant exhibits better performance than that doped with 4MeDI-Py. This result is related to the difference of fluorescent quantum yield between them. And 4MeDI-3N shows higher intensity of delay fluorescence in the transient EL, which indicated more effective TTA effect.

[1] Y. J. Tung, T. Ngo, M. Hack, J. Brown, N. Koide, Y. Nagara, Y. Kato, H. Ito, Dig. Tech. Pap. – Soc. Inf. Disp. Int. Symp. 2004, 35, 48.
[2] R. C. Chiechi, R. J. Tseng, F. Marchioni, Y. Yang, F. Wudl, Adv. Mater. 2006, 18, 325.
[3] Z. Q. Gao, B. X. Mi, C. H. Chen, K. W. Cheah, Y. K. Cheng, W. S. Wen, Appl. Phys. Lett. 2007, 90, 123506.
[4] Y. J. Tung, T. Nago, M. Hack, J. Brown, N. Koide, Y. Nagara, Y. Kato, H. Ito, SID 2004 Technical Digest. 2004, 35, 48.
[5] Y. Kijima, N. Asai, S. I. Tamura, Jpn. J. Appl. Phys., 1999, 38, 5274.
[6] M. T. Lee, C. H. Liao, C. H. Tsai, C. H. Chen, Adv. Mater., 2005, 17, 2497.
[7] H. Liu, G. Cheng, D. Hu, F. Shen, Y. Lv, G. Sun, B. Yang, P. Lu, Y. Ma, Adv. Funct. Mater. 2012, 22, 2830.
[8] V. Sivasubramaniam, F. Brodkorb, S. Hanning, H. P. Loebl, V. van Elsbergen, H. Boerner, U. Scherf, M. Kreyenschmidt, J. Fluor. Chem. 2009, 130, 640.
[9] M. Y. Wong, E. Zysman-Colman, Adv. Mater. 2017, 29, 1605444.
[10] W. Zeng, H. Y. Lai, W. K. Lee, M. Jiao, Y. J. Shiu, C. Zhong, S. Gong, T. Zhou, G. Xie, M. Sarma, K. T. Wong, C. C. Wu, C. Yang, Adv. Mater. 2018, 30, 1704961.
[11] V. Jankus, C.-J. Chiang, F. Dias and A. P. Monkman, Adv. Mater. 2013, 25, 1455.
[12] K. H. Kim, J. Y. Baek, C. W. Cheon, C. K. Moon, B. Sim, M. Y. Choi, J.-J. Kim, Y.-H. Kim, Chem. Commun. 2016, 52, 10956.
[13] D. Di, L. Yang, J. M. Richter, L. Meraldi, R. M. Altamimi, A. Y. Alyamani, D. Credgington, K. P. Musselman, J. L. MacManus-Driscoll, R. H. Friend, Adv. Mater. 2017, 29, 1605987.
[14] L. S. Cui, H. Nomura, Y. Geng, J. U. Kim, H. Nakanotani, C. Adachi, Angew. Chem. Int. Ed. 2016, 56, 1571.
[15] Q. Zhang, J. Li, K. Shizu, S. Huang, S. Hirata, H. Miyazaki, C. Adachi, J. Am. Chem. Soc. 2012, 134, 14706.
[16] P. Y. Chou, H. H. Chou, Y. H. Chen, T. H. Su, C. Y. Liao, H. W. Lin, W. C. Lin, H. Y. Yen, I. C. Chen, C. H. Cheng, Chem. Commun. 2014, 50, 6869-6871.
[17] Y. H. Chen, C. C. Lin, M. J. Huang, Kevin Hung, Y. C. Wu, W. C. Lin, R.-W. C.-C., H. W. Lin, C. H. Cheng, Chem. Sci. 2016, 7, 4044.
[18] M. Aydemir, G. Haykır, A. Battal, V. Jankus, S. K. Sugunan, F. B. Dias, H. Al-Attar, F. Türksoy, M. Tavasl., A. P. Monkman, Org. Electron. 2016, 30, 149.
[19] X. Tang, Q. Bai, T. Shan, J. Li, Y. Gao, F. Liu, H. Liu, Q. Peng, B. Yang, F. Li, P. Lu, Adv. Funct. Mater. 2018, 28, 1705813.
[20] Y. Li, F. Li, H. Zhang, Z. Xie, W. Xie, H. Xu, B. Li, F. Shen, L. Ye, M. Hanif, D. Ma, Y. Ma, Chem. Commun. 2007, 231.
[21] J. Y. Hu, Y. J. Pu, F. Satoh, S. Kawata, H. Katagiri, H. Sasabe, J. Kido, Adv. Funct. Mater. 2014, 24, 2064.
[22] D. Di, L. Yang, J. M. Richter, L. Meraldi, R. M. Altamimi, A. Y. Alyamani, D. Credgington, K. P. Musselman, J. L. MacManus-Driscoll, R. H. Friend, Adv. Mater. 2017, 29, 1605987.
[23] Xiaozhang Zhu, Chikahiko Mitsui, Hayato Tsuji, Eiichi Nakamura, J. AM. CHEM. SOC. 2009, 131, 13596.
[24] Y. Wei, P. J. Liu, R. H. Lee, C. P. Chen, RSC Adv. 2015, 5, 7897.
[25] Q. Yan, Y. Guo, A. Ichimura, H. Tsuji, E. Nakamura, J. Am. Chem. Soc. 2016, 138, 10897.
[26] H. A. Hammond, D. E. DeMeyer, Jack L. R. Williams, J. Am. Chem. Soc. 1969, 91 (18), 5180.
[27] Brian Wardle (2009). Principles and Applications of Photochemistry Hoboken: John Wiley & Sons, Ltd
[28] X. Yuan, W. Zhang, L. H. Xie, J. Ma, W. Huang, W. Liu, J. Phys. Chem. B 2015, 119, 10316.
[29] H. Inomata, K. Goushi, T. Masuko, T. Konno, T. Imai, H. Sasabe, J. J. Brown, C. Adachi, Chem. Mater. 2004, 16, 1285.
[30] H. F. Chen, S. J. Yang, Z. H. Tsai, W. Y. Hung, T. C. Wang, K. T. Wong, J. Mater. Chem. 2009, 19, 8112.
[31] J. Shi, C. W. Tang, C. H. Chen, U.S. Patent 5646948, 1997.
[32] S. O. Jeon, Y. M. Jeon, J. W. Kim, C. W. Lee, M. S. Gong, Synth. Met. 2007, 157, 558.
[33] T. L. Ye, S. Y. Shao, J. S. Chen, L. X. Wang, D. G. Ma, ACS applied materials & interfaces,2011, 3, 410-416.
[34] H. Sasabe, J. Kido, Chem. Mater. 2011, 23, 621-630.
[35] C. A. Parker, C. G. Hatchard, Trans. Faraday. Soc. 1961, 57, 1894.
[36] C. A. Parker, C. G. Hatchard, Proc. Chem. Soc. 1962, 147.
[37] V. Jankus, C. Winscom, A. P. Monkman, J. Chem. Phys. 2009, 130.
[38] B. Pan, H. Huang, X. Yang, J. Jin, S. Zhuang, G. Mu, L. Wang, J. Mater. Chem. C 2014, 2, 7428.
[39] P. F. Duan, N. Yanai, Y. Kurashige, N. Kimizuka, Angewandte Chemie 2015, 54, 7544.
[40] D. Song, S. Zhao, Y. Luo, H. Aziz, Appl. Phys. Lett. 2010, 97, 243304.
[41] K. Masui, H. Nakanotani, C. Adachi, Org Electron. 2013, 14, 2721.
[42] C. Y. Chan, L. S. Cui, J. U. Kim,H. Nakanotani, C. Adachi, Adv. Funct. Mater. 2018, 28, 1706023.
[43] S. H. Lin, F. I. Wu, H. Y. Tsai, P. Y. Chou, H. H. Chou, C. H. Cheng, R. S. Liu, J. Mater. Chem. 2011, 21, 8122.
[44] Y. H. Chen, H. H. Chou, T. H. Su, P. Y. Chou, F. I. Wu, C. H. Cheng, Chem. Commun. 2011, 47, 8865.
[45] H. H. Chou, Y. H. Chen, H. P. Hsu, W. H. Chang, Y. H. Chen, C. H. Cheng, Adv. Mater. 2012, 24, 5867.
[46] Q. Zhang, J. Lee, K. Shizu, S. Huang, S. Hirata, H. Miyazaki, C. Adachi, J. Am. Chem. Soc. 2012, 134, 14706.
[47] Y. Lee, J. Kim, S. Kwon, C. K. Min, Y. Yi, J. W. Kim, B. Koo, M. P. Hong, Org. Electron. 2008, 9, 407.