臺灣博碩士論文加值系統

本論文於混合排列向列型液晶盒元件(Hybrid Alignment Nematic Liquid Crystal Device, HAN-LCD )的水平配向基板表面塗佈二氧化矽奈米粒子(SiO_2 nanoparticle)，研究其雙穩態(Bistable)的特性，藉由施加相反極性的脈衝電壓(Pulse Voltage)於雙穩態HAN-LCD，將可切換元件的亮態及暗態兩種穩態。
論文中已證實，SiO_2奈米粒子於水平配向基板表面的塗佈濃度以及元件內離子雜質的存在，都對元件的雙穩態特性產生影響。另根據元件內的自由能密度的計算，由帶負電的SiO_2奈米粒子及離子雜質所造成的內建電場，可穩定元件的暗態。
此外，本元件除了用於雙穩態顯示之外，同時具有動態顯示的特性。與一般HAN-LCD作比較，發現雙穩態液晶元件除了上升時間較長之外，其餘動態特性與一般HAN-LCD無明顯差別，故此元件可依產品使用的需求操作於動態顯示或雙穩態顯示，因此為此類型雙穩態元件最大特點。

The bistable hybrid-aligned nematic liquid crystal device (HAN-LCD) was fabricated with silica nanoparticle-coated polyimide (PI) alignment films. The triboelectrically-charged silica nanoparticles and the existence of impurity ions in the LC can cause an internal electric field to stabilize the device in the homeotropic state (dark state) after turning off the driving voltage. For switching back to the HAN state (bright state) from the homeotropic state, a voltage pulse with proper polarity was applied for changing the ion distribution in the device. The capability of controlling bistability was achieved through modification of the ion density in the LC layer and the surface properties of the homogeneous PI alignment layer.
In addition, the electro-optical characteristics of the bistable HAN-LCD operated in the dynamic mode were studied and compared with the normal HAN-LCD. Our proposed device is not only being able to operate in bistable display mode, but also in dynamic display mode when appling an AC voltage.

摘要........................................................................................................................I
Abstract...............................................................................................................II
致謝.................................................................................................................... III
目錄.................................................................................................................... IV
圖目錄................................................................................................................VII
表目錄................................................................................................................ X
第一章 緒論.........................................................................................................1
1.1 前言......................................................................................................1
1.2 實驗簡介..............................................................................................2
第二章 雙穩態顯示器.........................................................................................4
2.1 雙穩態定義..........................................................................................4
2.2 電泳顯示器……..................................................................................4
2.3 ZBD顯示器..........................................................................................5
2.4雙穩態HAN-LCD…………................................................................7
2.4.1 HAN-LCD簡介……….……………….……………………….7
2.4.2 液晶層摻雜奈米粒子之雙穩態HAN-LCD……….…………..8
2.4.3 膠體與電雙層相關理論………………...……....…….……...10
2.4.4水平配向層表面塗佈奈米粒子之雙穩態HAN-LCD………13
第三章 理論………….......................................................................................16
3.1 液晶簡介…………...........................................................................16
3.2液晶物理性質....................................................................................16
3.2.1 液晶的雙折射性.....................................................................16
3.2.2 介電非均向性.........................................................................18
3.2.3 連續彈性位能理論….............................................................19
3.2.4 錨定力與極化錨定能………………………………………..21
3.2.5 屈電效應….………………………………………………….23
3.2.6 液晶盒內的自由能密度………….………………………….26
第四章 量測工作原理………...........................................................................27
4.1預傾角量測.........................................................................................27
4.2錨定能量測理論.................................................................................31
4.3 LCR Meter量測離子濃度工作原理..................................................34
4.4 接觸角與表面能理論........................................................................39
第五章 實驗樣品製備及量測...........................................................................42
5.1 使用材料介紹……............................................................................42
5.2 奈米粒子溶液製備............................................................................43
5.3 雙穩態HAN-LCD製作....................................................................44
5.4實驗量測……….................................................................................47
5.4.1 偏光顯微鏡觀察.....................................................................47
5.4.2高解析場發射掃描式電子顯微鏡觀察..................................47
5.4.3 液晶盒的雙穩態測試…….....................................................48
5.4.4 預傾角量測架構.....................................................................49
5.4.5 錨定能量測架構.....................................................................50
5.4.6 LCR Meter離子濃度量測架構.............................................51
5.4.7 反應時間量測架構.................................................................52
5.4.8 表面能量測架構……………………………….…………….54
第六章 實驗結果與討論...................................................................................55
6.1 水平配向基板表面微結構………………………………………....55
6.2 HAN-LCD雙穩態元件偏光觀察…………………………………..57
6.3 SiO_2奈米粒子對雙穩態元件的影響…………….….……………...58
6.4 SiO_2奈米粒子塗佈濃度對雙穩態特性的影響….….……………...61
6.5 雙穩態HAN-LCD的光電特性量測……………………….……...63
6.5.1 正極性脈衝電壓強度變化對元件光電特性影響…….…..64
6.5.2 正極性脈衝電壓持續時間變化對元件光電特性影響…...65
6.5.3負極性脈衝電壓持續時間變化對元件光電特性影響…...66
6.6 SiO_2奈米粒子塗佈濃度對預傾角與錨定能的變化…….………...68
6.7液晶盒內離子濃度對元件雙穩態的影響………………………….69
6.8雙穩態HAN-LCD之電荷估算…………………………………….71
6.9 元件內的自由能密度討論…………………………………………74
6.10 雙穩態HAN-LCD的動態光電特性……………………………..77
6.10.1 穿透率對交流電壓曲線圖……………...…………………77
6.10.2反應時間量測…………………….…...…………..……….79
6.11水平配向基板的表面能變化……………………………………..81
第七章 結論…………………………………………………………………...83
參考文獻.............................................................................................................85

[1] Dozov and M. Nobili, “Fast bistable nematic display using monostable surface switching,” Appl. Phys. Lett. 70, 1179–1181 (1996).
[2] J. C. Jones, “Novel geometries of the zenithal bistable device,” SID Symp. Digest 37, 1626–1629 (2006).
[3] J. C. Jones, “The zenithal bistable device: from concept to consumer,” SID Symp. Digest 38(1),1347–1350 (2007).
[4] R. M. Amos, “Optimizing the zenithal bistable display,” SID Symp. Digest 120, 1577–1580 (2009).
[5] D.-K. Yang, “Flexible bistable cholesteric reflective displays,” J. Disp. Technol. 2, 32 (2006).
[6] R. Hattori and S. Yamada, “A quick-response liquid-powder display (QR-LPD®) with plastic substrate,” J. Soc. Inf. Display 12, 405–409 (2004).
[7] Y. Masuda and N. Nihei, “A reflective-display QR-LPD,” J. Soc. Inf. Display 14, 443–447 (2006).
[8] L. S. Park and H. S. Choi, “Photolithographic process of microcapsule sheet for electrophoretic display, ” Mater. Sci. Eng. 24, 143–146 (2004).
[9] R.-C. Liang, J. Hou, and H. Zang, “Microcup® display: electronic paper by roll-to-roll manufacturing processes,” J. Soc. Inf. Display 11/4, 621–628 (2003).
[10] D. Sikharulidze, “Nanoparticles: An approach to controlling an electro-optical behavior of nematic liquid crystals,” Appl. Phys. Lett. 86, 0330507 (2005).
[11] D. Sikharulidze, U.S. Patent No.7,264,851, B2 (2007).
[12] C.-Y. Huang,C.-C. Lai, and Y. H. Tseng, “Silica-nanoparticle-doped nematic display with multistable and dynamic modes,” Appl. Phys. Lett. 92,221908 (2008).
[13] C.-Y. Huang and C.-C. Lai, “Switching characteristics of silica nanoparticle-doped dual-mode liquid crystal device,” Jpn. J. Appl. Phys. 49, 028003 (2010).
[14] C.-Y. Huang and J.-H. Chen, “Effect of polyimide concentration on the memory stability of the silica-nanoparticle-doped hybrid aligned nematic cell,” Jpn. J. Appl. Phys. 50, 021702 (2011).
[15] C.-Y. Huang and J.-H. Chen, “Stability in the memory state of the silica nanoparticles-doped hybrid aligned nematic device,” J. Appl. Phys. 109, 023505 (2011).
[16] D. Sikharulidze, U.S. Patent No. 7,430,030, B2 ( 2008).
[17] 劉瑞祥, 液晶之基礎與應用, 國立編譯館, 台北 (1996).
[18] 陳連春, 彩色液晶顯示器, 建興出版社, 台北 (2000).
[19] M. Kleman and O. D. Lavrentovich, Soft Matter Physics: An Introduction, 1st ed. Springer, New York, p.157,158 (2002).
[20] 許唐維, “摻雜二氧化矽奈米粒子之液晶元件特性研究及應用,” 國立交通大學影像與生醫光電所碩士論文 (2011).
[21] 張有義, 郭蘭生, 膠體及界面化學入門, 高立圖書有限公司 (1996).
[22] T. Bert and H. D. Smet, "Dielectrophoresis in electronic paper," Displays 24, 223-230 (2003).
[23] P. Sarkar and P. S. Nicholson, "Electrophoretic deposition(EPD) : mechanisms, kinetic, and application to ceramics," J. Am. Ceram. soc. 79, 1987-2002 (1996).
[24] P. G. de Gennes and J. Prost, The Physics of Liquid Crystals, Oxford Science, New York, p41–81, p98–127 (1995).
[25] A. J. Davidson, ”Flexoelectric switching in a bistable nematic device,” A thesis submitted for the degree of Doctor of Philosophy, Department of Mathematic, University of Strathclyde, UK (2004).
[26] L. M. Blinov, M. Ozaki, and K. Yoshino, “Flexoelectric polarization in nematic liquid crystals measured by a field on–off pyroelectric technique,” J. Exp. Theor. Phys. Lett. 69, 236–242 (1999).
[27] S. J. Hwang and M. H. Hsu, “Heterodyne method for determining the surface tilt angle of nematic liquid-crystal displays,” J. Soc. Inf. Display. 14, 1039 (2006).
[28] X. Nie, Y.-H. Lin, T. X. Wu, H. Wang, Z. Ge, and S.-T. Wu, “Polar anchoring energy measurement of vertically aligned liquid crystal cells,” J. Appl. Phys. 98, 013516 (2005).
[29] Y. A. Nastishin, R. D. Polak, S. V. Shiyanovskii, and O. D. Lavrewntovich, “Determination of nematic polar anchoring from retardation versus voltage measurements,” Appl. Phys. Lett. 75, 12 (1999).
[30] Lambient TechnologiesTM , “Application Note 2—Dielectric Properties.”
[31] S. Uemura, “Ionic contribution to the complex dielectric constant of a polymer under dc bias,” J. Polym. Sci. 10, 2155 (1972).
[32] S. Uemura, “Low-frequency dielectric behavior of poly(vinylidene fluoride),” J. Polym. Sci. 12, 1177 (1974).
[33] D. K. Owens and R. C. Wendt, “Estimation of the surface free energy of polymers,” J. Appl. Polym. Sci. 13, 1741 (1969).
[34] E. Lueder, Liquid Crystal Displays: Addressing Schemes and Elecrooptical Effects, 2nd ed., Wiley, Chichester (2010).
[35] X. Nie, R. Lu, H. Xianyu, T. X. Wu, and S. T. Wu, ”Anchoring energy and cell gap effects on liquid crystal response time,” J. Appl. Phys. 101, 103110 (2007).