Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/9080
標題: 以增強電場提升粉末無機電激發光元件特性
Improved Performance of Powder Inorganic Electroluminescent Devices with Enhanced Electric Field
作者: 陳國峰
Chen, Kuo-Feng
關鍵字: 粉末無機電激發光元件
Powder Inorganic Electroluminescent
奈米碳管
駐極體
Carbon nanotube
Electret
出版社: 電機工程學系所
引用: [1].衣立新, “無機薄膜電致發光顯示器的研究進度”, 大陸北方交通大學光電子技術研究所, (2000). [2].J. Heikenfeld, A. J. Steckl, “Low-Cost Display Technology Utilizing Thick Dielectric Electroluminescent (TDEL) Devices on Glass Substrates”, Proc. SID Vehicle Displays, (2001). [3].Chanaka Munasinghe, Jason Heikenfeld, Robert Dorey, Roger Whatmore, Jeffrey P. Bender, John F. Wager, Andrew J. Steckl, “High Brightness ZnS and GaN Electroluminescent Devices Using PZT Thick Dielectric Layers”, IEEE TRANSACTIONS ON ELECTRON DEVICES, 52,, pp.94, (2005). [4].C. Munasinghe, A.J. Steckl, “GaN:Eu electroluminescent devices grown by interrupted growth epitaxy”, Thin Solid Films, 496, pp.636-642, (2006). [5].Y. H. Son, S. J. Kim, Y. M. Kim, G. E. Jang, M. S. Yoon, S. C. Ur, S. L. Ryu, S. Y. Kweon, “Characteristics of BaTiO3-PVDF 0-3 Composite Film for Inorganic .Electroluminescence Device”, Integrated Ferroelectrics, 98, pp.183–191, (2008). [6].J.F. Wager, “Electrical characterization of thin film electroluminescent devices”, Annual review. Material of sciences, 27, pp.223, (1997). [7].D. Poelman., “Luminescent characterization of CaAl2S4:Eu powder”, Journal of Luminescent, 126, pp.508, (2007). [8].MIYATA TOSHIHIRO, MOCHIZUKI YU, MINAMI TADATSUGU, “Blue luminescence from Eu-activated BaO-Based multicomponent oxide phosphor thin films”, SID, pp.1613, (2005). [9].Tanaka, “The Inorganic Electroluminescent Studies in Tottori University- in Memory”, IDW, pp.1065, (2004). [10].Yoshimasa A. Ono, “Electroluminescent displays : Chap. 5 MaterialsRequirements”, 61, pp.121-139, (1995). [11].Destriau. G, “Recherches sur les seintiUafion de zinc aux rayons”, J. Chem. Phys., 33, pp.587, (1936). [12].A. Vecht, N. J. Werring, and P. J. F. Smith, “High-efficiency d.c. electroluminescence in ZnS (Mn, Cu)”, Br. J. Appl. Phys., 1, pp.134, (1968). [13].D. Kahng, “Electroluminescence of rare-earth and transition metal molecules in II-VI compounds via impact excitation”, Appl. Phys. Lett., 13, pp.210, (1968). [14].T. Inoguchi, M. Takeda, Y. Kakihara, Y. Nakata, and M. Yoshida, “Stable high-brightness thin-film electroluminescent panels”, Digest of SID International Symposium, 84, (1974). [15]. Jason C. Heikenfeld and Andrew J. Steckl, “Inorganic EL Displays at the Crossroads”, SID, (2003). [16].Dirk Poelman, “Advances in sulfide phosphors for displays and lighting”, J Mater Sci. Mater Electron, 20, pp.S134, (2009). [17].王永生, “無機薄膜電激發光研究進展”, 功能材料, 30, pp.2, (2002). [18].Noboru. M., “High-luminescence blue-emitting BaAl2S4:Eu thin film electroluminescent devices”, Japan Journal of Applied Physics, 38, pp.1291, (1999). [19].M. Takeda, Y. Kanatani, H. Kishishita, T. Inoguchi, K. Okano, “Practical Application Technologies of Thin-Film Electroluminescent Panels”, in Proc. Soc. Inf. Disp., 22, pp.57, (1981). [20].X. Wu, and D. Carkner, “TDEL: technology evolution in inorganic electroluminescence”, in Digest 2005 SID Int. Symp. Society of Information Display, pp.108, (2005). [21].曹允,交流粉末電致發光顯示板原理及其應用, 光電子技術, 第22卷, 第4期, (2002) [22]. 蘇水祥, 新型平面薄膜電激發光顯示器, 科學發展月刊, 第29卷, 第10期 [23].徐敘瑢編著、陳憲偉校訂, “光電材料與顯示技術”,五南出版社. [24].T. Inoguchi, C. Suzuki, N &quot;Structure and Characteristics of High-Brightness, Long-Life Thin EL Panel&quot;,ikkei Electronics, pp.84, (1974). [25].C. N. King, “electroluminescent displays”, J. Vac. Sci. Technol. American, 14, pp.1729, (1996). [26].K. Neyts, “Numerical simulation of charge transfer and light emission in SrS:Ce thin-film electroluminescent devices”, IEEE Trans. Electron. 43, pp.1343, (1996). [27].A. N. Krasnov, “Electroluminescent displays: history and lessons learned Displays”. 24, pp.73. (2003). [28].J. Heikenfeld and A. J. Steckl, “Electroluminescent devices using a high-temperature stable GaN-based phosphor and thick-film dielectric layer”, IEEE Trans. Electron Devices. 49, pp.557, (2002). [29].J. F. Wager, J. C. Hitt, B. A. Baukol, and J. P. Bender, D. A. Keszler, “Luminescent impurity doping trends in alternating-current thin-film electroluminescent phosphors”, J. Lumin. 97, pp.68, (2001). [30].N. Shepherd, D. C. Morton, E. W. Forsythe, and D. Chiu, “The influence of insulator properties on the electro-optical performance of flexible ZnS:ErF3 alternating current thin film electroluminescent devices”, Thin Solid Films, 515, pp.2342, (2006). [31].J. S. Kim, S. G. Lee, H. L. Park, J. Y. Park, and S.D. Han, “Optical and electrical properties of ZnGa2O4/Mn2+ powder electroluminescent device”, Mater. Lett. 58, pp.1354, (2004). [32].J. H. Park, S. H. Lee, J. S. Kim, A. K. Kwon, H. L. Park, and S. D. Han, “White-electroluminescent device with ZnS:Mn, Cu, Cl phosphor”, J. Lumin. 126, pp.566, (2007). [33].S. D. Han, I. Singh, D. Singh, Y. H. Lee, G. Sharma, and C. H. Hana, “Crystal growth of electroluminescent ZnS:Cu,Cl phosphor and its TiO2 coating by sol–gel method for thick-film EL device”, J. Lumin., 115, pp.97, (2005). [34].M. J. Bae, S. H. Park, T. W. Jeong, J. H. Lee, I. T. Han, Y. W. Jin,J. M. Kim, J. Y. Kim, J. B. Yoo, and S. G. Yu, “Carbon nanotube induced enhancement of electroluminescence of phosphor”, Appl. Phys. Lett., 95, pp.071901, (2009). [35].S. H. Jo, Y. Tu, Z. P. Huang, D. L. Carnahan, D. Z. Wang, and Z. F. Ren, “Effect of length and spacing of vertically aligned carbon nanotubes on field emission properties”, Appl. Phys. Lett., 82, pp. 3520, (2003). [36].K. W. Lee, S. P. Lee, H. Choi, K. H. Mo, J. W. Jang, H. Kweon, and C. E. Lee, “Enhanced electroluminescence in polymer-nanotube composites”, Appl. Phys. Lett., 91, pp. 023110, (2007). [37].J. H. Choi, S. H. Choi, J. H. Han, J. B. Yoo, H. Y. Park, T. Jung, S. G. Yu, I. T. Han, and J. M. Kim, “Enhanced electron emission from carbon nanotubes through density control using in situ plasma treatment of catalyst metal,” Appl. Phys. Lett., 94, pp. 487, (2003). [38].S. Iijima,“ Helical Microtubules of Graphitic Carbon”, Nature, 354, pp. 56 (1991). [39].M. S. Dresseelhaus, G. Dresseelhaus, and R. Saito, “Physics of carbon nanotubes”, Carbon, 33, pp. 883 (1995). [40].P. J. F. Harris, S. C. Tsang, J. B. Claridge and M. L. H. Green, “High-resolution electron microscopy studies of a microporous carbon produced by arc-evaporation”, J. Chem. Soc., Faraday Trans, 90, pp. 2799 (1994). [41].P. Calvert,“ Strength in Disunity”, Nature, 357, pp. 365, (1992). [42].R.S. Ruoff, J. Tersoff, D.C. Lorents, S. Subramoney, and B. Chen, “ Radial Deformation of Carbon Nanotubes by Van-der-Waals”, Nature, 364, pp. 514, (1993). [43].R.S. Ruoff, D.C. Lorents, R. Laduca, S. Awaclalla, S. Weatherby, K. Parvin, and S. Subramoney, in Fullerenes:Recent Advances in the chemistry and Pyhsics of Fullerences and Related Materials, pp. 557, (1993). [44].P.M. Ajayan and S. Iijima, “Capillarity-Induced Filling of Carbon Nanotubes”, Nature, 361, pp.333, (1993). [45].P.M. Ajayan, T.W. Ebbesen, T. Ichihashi, S. Iijima, K. Tanigaki, and H. Hjura, “Opening Carbon Nanotubes with Oxygen and Implications for Filling”, Nature, 362, pp.522, (1993). [46].S.C. Tsang, Y.K. Chen, P.J.F. Harris, and M.L.H. Green, “A Simple Chemical Method of Opening and Filling Carbon Nanotubes”, Nature 372, pp.159, (1994). [47].C. Guerret-Piecourt, K.Le Bouar, A. Loiseau, and H. Pascard, “Relation Between Metal Electronic Structure and Morphology ol Metal Compounds Inside Carbon” Nanotubes”, Nature, 372, pp.761, (1994). [48].P.M. Ajayan, O. Stephan, P. Recllich, C. Colliex,“Carbon Nanotubes as Removable Templates for Metal-Oxide Nanocomposites and Nanostructures”, Nature, 375, pp.564, (1994). [49].S. Subramoney, M.J. Van Kavelar, R.S. Ruoff, D.C. Lorents, R. Malhotra, and A.J. Kazmer, in Fullerenes Recent Advances in the chemistry and Physics of Fullerences and Related Materials, (1994). [50].C. Niu, E. K. Sichel, R. Hoch, D. Moy, and H. Tennent, “High Power Electrochemical Capacitors Based on Carbon Nanotube Electrodes”, Appl. Phys. Lett., 70, pp.1480, (1997). [51].R. Martel, T. Schmidt, H. R. Shea, T. Hertel, and Ph. Avouris, “Single-Wall and Multi-Wall Carbon Nanotube Field-Effect Transistors”, Appl. Phys. Lett., 73, pp.2447, (1998). [52].M. Ge and K. Sattler, “Scanning Tunneling Microscopy of Single-Shell Nanotubes of Carbon”, Appl. Phys. Lett. 65, pp.2284, (1994). [53].P. Calvert,“ Strength in Disunity ” Nature, 357, pp.365, (1992). [54.].S.J. Tams, A.R.M. Verschueren, and C. Dekker, “Room-Temperature Transistor Based on a Single Carbon Nanotube”, Nature, 393, pp.49, (1998). [55].G. Nagy, M. Levy, R. Scarmozzino, R.M. Osgood, Jr. H. Dai, R.E. Smalley, and G.F. McLane, “ Carbon Nanotube Tipped Atomic Force Microscopy for Measurement of <100 nm Etch Morphology on Semiconductors”, Appl. Phys. Lett., 73, pp.529, (1998). [56].D.S. Bethune, C.H. Kiang, M.S. deVries, G. Gorman, R. Saroy, J. Vazguez, and R. Beyers, “Cobalt-Catalyzed Growth of Carbon Nanotubes with Single-Atomic-Layerwalls ”, Nature, 363, pp.605, (1993). [57] S. Yahachi and U. Sashiro, “Field emission from carbon nanotubes and its application to electron sources”, Carbon, 38, 169 (2000). [58].J.M. Lambert, P.M. Ajayan, P. Bernier, J.M. Planeix, V. Brotons, B. Coq, and J. Castaing, “Improving Conditions Towards Isolating Single-Shell Carbon Nanotubes”, Chem. Pyhs. Lett., 226, pp.264, (1994). [59].S. Subamoney, R.S. Ruoff. D.C. Lorents, and R. Malhotra, “Radial Single-Layer Nanotubes”, Nature, 366, pp.637, (1993). [60].S. Seraphin and D. Zhou, “Single-Walled Carbon Nanotubes Growing Radially from YC2 Particles”, Appl. Phys. Lett., 65, pp.1593, (1994). [61].T.W. Ebbesen, P.M. Ajayan, H. Hinram, and K.T Anigaki, “Role of Sp3 Defect Structures in Graphite and Carbon Nanotubes”, Nature, 367, pp.519 , (1994). [62].A. Thess, R. Lee, P. Nikolaev, H. Dai, P. Petit, J. Robert, C. Xu, Y.H. Lee, S.G. Kim, A.G. Rinzler, D.T. Colbert, G.E. Scuseria, D. Tomanek, J.E. Fischer, and R.E. Samlley, “Crystalline Ropes of Metallic Carbon Nanotubes”, Science, 273, pp.483, (1996). [63].Z.F. Ren, Z.P. Huang, J.W. Xu, J.H. Wang, P. Bush, M.P. Siega, and P.N. Provencio, “Synthesis of Large Array of Well-Aligned Carbon Nanotubes on Glass”, Science, 282, pp.1105, (1998). [64].Kei Murakoshi, Ken-ichi Okazaki, “Electrochemical potential control of isolated single-walled carbon”, Electrochimica Acta,50, pp.3069–3075, (2005). [65].Youngki Yoon, Jing Guo, “Analysis of Strain Effects in Ballistic Carbon Nanotube FETs”, IEEE Trans. Electron Devices, 54, pp. 1280, (2007). [66].Takerou Sakashita, Yuhei Miyauchi, Kazunari Matsuda, Yoshihiko Kanemitsu, “Plasmon-assisted photoluminescence enhancement of single-walled carbon nanotubes on metal surfaces”, App. Phy. Lett, 97, pp.063110, (2010). [67].Hongsik Park, Hyunjung Shin, Jin Ho Kim, Seungbum Hong, Jimmy Xu, “Memory effect of a single-walled carbon nanotube on nitride-oxide structure under various bias conditions”, App. Phy. Lett, 96, pp.023101, (2010). [68].成會明, 張勁燕, “奈米碳管”, (2004). [69].Dai H, Hafner JH, Rinzler AG, “Nanotubes as nanoprobes in scanning probe microscopy”, Nature, 384, pp.147, (1996). [70].Rinzler AG, Harner JH, Nikolaev P, “Unraveling Nanotubes: Field Emission from an Atomic Wire”, Science. 269, pp. 1550, (1995). [71].拓墣產業研究所整理, (2003) [72].White CT, Todorov TN, Nature, “Carbon nanotubes as long ballistic conductors”, 393, pp.240, (1998). [73].ZH Zhang, JC Peng, H Zhang. “Excited-state dynamics and carrier capture in InGaAs/GaAs quantum dots”, Appl Phys Lett, 79, pp.3520, (2001). [74].M Bockrath, DH Cobden, J Lu, AG Rinzler, RE Smalley, “Luttinger-liquid behaviour in carbon nanotubes”, Nature, 397, pp.598, (1999). [75].Chico L, Benedict LX, Louie SG, “Quantum conductance of carbon nanotubes with defects”, Phy Rev B., 54, pp.2600, (1996). [76].Frank S, Poncharal P, Wang ZL, “Carbon Nanotube Quantum Resistors”, Science, 280, pp.1744, (1998). [77].賽墨飛科技, 拉曼光譜在碳材料方面的應用, (2011). [78].Bacsa WS, Ugarte D, Chatelain A, “High-resolution electron microscopy and inelastic light scattering of purified multishelled carbon nanotubes”, Phy Rev B. 50, pp.15473, (1994). [79].Huong PV, Cavagnat R, Ajayan PM, “Temperature-dependent vibrational spectra of carbon nanotubes”, Phy Rev B, 51, pp.10048, (1995). [80].Pingheng Tan1, Shu-Lin Zhang1, Kwok To Yue, Fumin Huang, Zujing Shi, Xihuang Zhou, Zhennan Gu, “Comparative Raman Study of Carbon Nanotubes Prepared by D.C. Arc Discharge and Catalytic Methods”, J Ramn Spect, 28, pp.369, (1997) [81].李廷盛、尹其光等著。超聲化學,北京,科學出版社,(1995) [82].Z.P. Huang, J.W. Xu, Z.F. Ren, J.H. Wang, M.P. Siega, and P.N. Provencio,“ Growth of Highly Oriented Carbon Nanotubes by Plasma-Enhanced Hot Filament Chemical Vapor Deposition”, Appl. Phys. Lett., 73, pp.3845, (1998). [83].O. M. Kuttel, O. Groening, C. Emmenegger, and L. Schlapbach, “Electron Field Emission from Phase Pure Nanotube Films Grown in a Methane/Hydrogen Plasma”, Appl. Phys. Lett., 73, pp.2113, (1998). [84].Yan Chen, Sushil Patel, Yagu Ye, David T. Shaw, Liping Guo, “Field Emission From Aligned High-Density Graphitic Nanofibers”, Appl. Phys. Lett., 73, pp.2119, (1998). [85].Z. K. Tang, H. D. Sun, J. Wang,J. Chen, and G. Li, “Mono-Sized Single-Wall Carbon Nanotubes Formed in Channels of AlPO4-5 Single Crystal”, Appl. Phys. Lett., 73, pp.2287, (1998). [86].M. Sveningsson, R.-E. Morjan, O.A. Nerushev, Y. Sato, J. B&auml;ckstr&ouml;m, E.E.B. Campbell, F. Rohmund, “Raman spectroscopy and field-emission properties of CVD-grown carbon-nanotube films”, Appl Phy A., 73, pp. 409, (2001). [87].Charanjeet Singh, Milo S.P. Shaffer, Alan H. Windle, “Production of controlled architectures of aligned carbon nanotubes by an injection chemical vapour deposition method”, Carbon, 41, pp.359, (2003). [88].Xiomara Calderon-Colon, Huaizhi Geng, Bo Gao, Lei An,Guohua Cao, Otto Zhou, “A carbon nanotube field emission cathode with high current density and long-term stability”, Nanotechnology, 20, pp. 1, (2009). [89].C. Bower, R. Rosen, L. Jin J. Han, O. Zhou, “Deformation of carbon nanotubes in nanotube–polymer composites”, Appl Phys Lett, 74, pp. 3317, (1999). [90].K.Ogawa, Y.Tadakuma, K. Kawato, M. Nakanishi, Y.Miyashita, S. Yamashita, “A study of electroluminescent process and efficiency in ZnS particles”, IDW, pp.1605, (2005). [91].J.S. Kim, S.G. Lee, H.L. Park, J.Y. Park, S.D. Han, “Optical and electrical properties of ZnGa2O4/Mn2+powder electroluminescent device”, Materials Letters, 58, pp. 1354, (2004). [92].Seiji Yamashita, Tadanobu Satou, Masashi Shirata, Takafumi Noguchi, Kouji Kawato, KyouheiOgawa, “High brightness luminous Dispersion-type inorganic electroluminescence device”, IDW, pp. 1199, (2006). [93].X. Zhang and G. M. Sessler, “Charge dynamics in silicon nitride/silicon oxide double layers”, Appl. Phys. Lett. 78, pp.2757. (2001). [94].G. M. Sessler, “Charge storage in dielectrics”, IEEE Trans. Electr. Insulation. 24, pp.395, (1989). [95].Z. Xia, R. Gerhard-Multhaupt, W. Kunstler, A. Wedel, and R. Danz, J. Phys. D, “High surface-charge stability of porous polytetrafluoroethylene electret films at room and elevated temperatures”, Appl. Phys. 32, pp.83, (1999). [96].K. Kojima, A. Maeda, Y. Takai, and M. Ieda, Jpn. J. Appl. Phys. “Thermally Stimulated Currents from Polyethylene Terephthalate due to Injected Charges”, 17, pp.1735, (1978). [97].H. Amjadi and C Thielemann, “Silicon-based inorganic electrets for application in micromachined devices”, IEEE Trans. Electr. Insulation., 3, pp.494, (1996). [98].K Tanaka and S Okamoto, “Hot carrier type exchange in inorganic electroluminescent thin films”, Appl. Phys. Lett. 89, pp.203508, (2006). [99].J. Heikenfeld and A. J. Steckl, “Alternating current thin-film electroluminescence of GaN:Er”, Appl. Phys. Lett., 77, pp. 3520, (2000). [100].Z. f. Xia, S. S. Ma, X. L. Qiu, Y. W. Zhang, Journal of Electrostatics, “Influence of porosity on the stability of charge and piezoelectricity for porous polytetrafluoroethylene film electrets”, 58, pp.265, (2003). [101].S. N. Fedosov, A. E. Sergeeva, Journal of Electrostatics, “Model of polarization build-up during corona charging of ferroelectric polymers”, 30, pp.39, (1993). [102].M. Paajanen, J. Lekkala, K. Kirjavainen, Sensors and Actuators, “ElectroMechanical Film (EMFi) — a new multipurpose electret material”, pp.84, (2000). [103]. K. Dworecki, T. Hasewaga, K. Sudlitz, and S. Wasik, “Modification of electrical properties of polymer membranes by ion implantation”, Nuclear instruments and methods in physics research B, 166, pp. 646, (2000). [104].P. D. Rack, P. H. Holloway, ”The structure, device physics, and material properties of thin film electroluminescent displays”, Mater. Sci. Engineering, 21, pp.171, (1998).
摘要: 本論文主要研究以增強電場來降低粉末無機電激發光元件(Powder Electroluminescent Device, PDEL)的驅動電壓及提升元件發光效率。本論文所採用在PDEL元件內增強電場的方式有兩種:一是電場放大,二是內建電場。前者主要是在元件介電層摻入單壁或多壁奈米碳管,以奈米碳管增強電場效應;後者主要是在元件結構中加入一駐極體層,並對其充電,形成內建電場。 在電場放大部份,我們首先在PDEL元件介電層摻入單壁奈米碳管,稱為SWNT-PDEL元件,奈米碳管比例為0.5-5 wt%。在亮度400 cd/m2及頻率1 kHz的條件下,與傳統PDEL元件比較,消耗電流降低6 mA,消耗功率可降低30%以上,而元件發光效率增加50 %。奈米碳管具有電場放大的功能其電場增強因子定義為β,電場增強因子會提高PDEL元件的電子於介電層介面間聚集量而增強電場,另外奈米碳管具有短通道及低能障特性能在幾無功率耗損條件下增加SWNT-PDEL元件介電層介面感應電荷聚集量提高電場。其次,在PDEL元件介電層摻入多壁奈米碳管,稱為MWNT-PDEL元件,奈米碳管比例為0.5‒2 wt%。在亮度100 cd/m2的條件下,與傳統PDEL元件比較,0.5 wt%、1 wt%、1.5 wt%、2 wt% 的MWNT-PDEL元件消耗功率分別降低33 %、30 %、25 %、16 %。在同消耗功率(10.75 mW)下比較,MWNT-PDEL元件發光效率分別增加80.5 %、65.4 %、34.1 %、27.8 %。以0.5 wt%的MWNT-PDEL元件可達最佳1.44 lm/W的發光效率。MWNT-PDEL元件在低輸入功率(10.75 mW)及低亮度(100 cd/m2)條件下,低MWNT摻雜的元件有更佳特性出現,且有較高的元件重複性及可靠度。比較多壁及單壁奈米碳管的電場增強因子β,單壁奈米碳管電場增強因子β為2000,而多壁奈米碳管電場增強因子β值為2500。所以PDEL元件加入多壁奈米碳管後更可有效發揮電場放大功能降低元件消耗功率及增加發光效率。 在內建電場部份,我們在PDEL元件結構中加入累電層及防漏電層,稱為EFBI-PDEL元件。累電層材料為有機的PET 膜及無機的矽基薄膜,而防漏電層則採用無機的矽基材料。以PET 膜為累電層時,與傳統PDEL元件比較,在驅動頻率為40 kHz的條件下,起始電壓可降低30 V (或42 %),以固定偏壓300 V驅動,元件亮度提升162.9 cd/m2(或34 %)。而採用矽基薄膜為累電層時,於同亮度269 cd/m2下比較傳統與150 度退火累電的EFBI-PDEL元件,驅動電壓降低61.4 V(或20.5 %),而固定驅動電壓300 V及頻率10 kHz時,EFBI-PDEL元件較傳統元件亮度增加128 cd/m2 (或47 %)。EFBI-PDEL元件利用累電後的駐極體加入PDEL結構中,累電駐極體的內建電荷會在PDEL元件中產生內建電場。PDEL元件發光原理為使用外加驅動電場激發螢光粉後發光,因為在元件結構中加入了內建電場的關係,故可以減少外加驅動電場進而達到降低驅動電壓及元件消耗功率的目的。
This work proposes a new method to reduce the power consumption of Inorganic PDEL (Powder Electroluminescent Devices) and enhance its luminous efficiency. This work proposes two method includes enhance electric field and electric field buildi-in. The enhance electric field method by introducing single wall carbon nanotube (SWNT) and multi wall carbon nanotube (MWNT) into the dielectric film of PDEL devices and creates new PDEL device structure. The electric field build-in method by introducing a charged electret into PDEL devices to decrease the driving voltage. First part proposes a new method to enhance electric field. The composite dielectric layer was formed by adding Carbon nanotube (CNT) into the dielectric layer of a PDEL component. With mixing SWNT (Single wall carbon nonatube), and content of SWNT in composite paste varied from 0 to 5 wt%. The current consumption decreased 6mA. The power consumption decreased 30 %. The luminous efficiency increased 50 % at the brightness of 400 cd/m2 and the operation frequency of 1 kHz, respectively. With mixing MWNT (Multi wall carbon nonatube), and content of MWNT in composite paste varied from 0.5 to 2 wt%. The power consumption decreased 16-33 %. The luminous efficiency increased 27.8-80.5 % at the brightness of 100 cd/m2 and the operation frequency of 1 kHz, respectively. The device power consumption is decreased by increasing excited electrons to collide luminescence center to produce higher luminance, which of these behaviors are benefited from CNT enhanced filed (Efield=ED+β EC、Efield=Device total Electric field、 ED=Device dielectric electric field、 β EC=Mixing CNT enhance electric field for PDEL device). The SWNT and MWNT field enhancement factor (β) were 2000 and 2500, respectively. Dispersing MWNT into PDEL device can improve device performace better than SWNT due to largen β values of MWNT. Second part proposes a new method to electric field buildi-in, we introduce a electret and protection layer (silicon base material) into PDEL devices to decrease the driving voltage. The existing electret lowered driving voltage of the PDEL device and thus increased its luminance. With electret was PET (polyethylene terephthalate, PET) material. At the operation frequency of 40 kHz, the trun on voltage of the EFBI-PDEL device decreased by 30 V (or 42 %), while under the ac voltage of 300 V, the brightness of the EFBI-PDEL device increased by 169.2 cd/m2 (or 34%) as compared to the uncharged device. With electret was silicon base material. At the brightness of 269 cd/m2, the driving voltage of the EFBI-PDEL device charged at 150 °C decreased by 61.4 V (or 20.5%), while under the ac voltage of 300 V, the brightness of the EFBI-PDEL device increased by 128 cd/m2 (or 47%) as compared to the uncharged device. The decreased driving voltage and enhanced brightness results from that the built-in electric field increases the electron energy in the conduction band of the phosphor layer and thus more electron impact ionization occurs to enhance luminance. The electret is made of materials which can be electrically charged. By using a discharging process, electrical charges can be injected into the electret and trapped in defect sites. These trapped charges create an electrostatic field to improve the performance of PDEL devices. This study developed a novel EFBI-PDEL device.
URI: http://hdl.handle.net/11455/9080
其他識別: U0005-2408201209145100
文章連結: http://www.airitilibrary.com/Publication/alDetailedMesh1?DocID=U0005-2408201209145100
Appears in Collections:電機工程學系所

文件中的檔案:

取得全文請前往華藝線上圖書館



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.