有机薄膜电致发光器件（OLED）研究和研制
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摘要
有机薄膜电致发光器件(OLED)自20世纪80年代末成为电子显示领域一颗耀眼的明星。它具有低压直流驱动、主动发光、色彩饱和度好、视角宽等一系列优点，在照明光源、光电耦合器和平板显示等光电领域具有诱人的前景。目前，OLED在小型平板显示领域如汽车仪表、手机屏和数码相机显示屏等方面已经投入商用。然而，OLED还存在一些问题，特别是在稳定性和寿命方面仍有待提高。
本文鉴于高分子聚合物在稳定性方面所特有的优势，研制了高分子聚合物掺杂小分子荧光材料的OLED。采用直流磁控反应溅射法沉积阳极ITO薄膜，旋涂法沉积有机膜，直流磁控溅射法或真空蒸镀法沉积Al阴极，制备了8-羟基喹啉铝(AlQ)绿色OLED。并在此基础上对一些制备参数进行优化，得到最大发光亮度为18.8cd／m~2的OLED。
本文首先探讨了在转速固定的情况下双层结构器件中空穴传输层PVK含量以及发光层中聚乙烯基咔唑(PVK)、AIQ和2-(4-联苯基)-5-(4-丁基苯基)-1，3，4-噁二唑(PBD)各物质配比对器件性能的影响，通过观察和比较器件的亮度、稳定性，确定了空穴传输层和发光层中各种物质的最佳含量。
本文还研究了Al阴极厚度和ITO阳极表面处理对器件性能的影响。实验结果表明：Al阴极存在最佳厚度使OLED的发光亮度和稳定性达到最优化；ITO阳极表面处理改变了薄膜表面形貌，提高了OLED的亮度、稳定性和流明效率。
再者，本文研究了器件结构对OLED性能的影响。实验结果表明，单层结构器件性能最差，双层结构器件性能次之，三层结构器件性能最佳。论文还探讨了三层结构器件性能的优化。
本文的创新之处在于：具体探讨了真空蒸镀法和直流磁控溅射法沉积Al阴极对双层器件性能的影响，并对造成这种差异的原因进行了具体分析和探讨。
Organic light-emitting diodes (OLED) have become a shining star in the electronic display field since the end of the 1980s. This technology exhibits bright prospect in photoelectricity field due to its advantages of low DC drive voltage, active luminescence, excellent hue saturation, wide visual angle, etc. Nowadays, small-area OLED have been commercially produced in the area of mobile meters, screens of mobile phones and digital cameras, etc. However, some problems, especially on stability and lifetime, still need to resolve.
In respect of the excellent stability of polymer, the OLED using polymer doped with small molecular materials is fabricated. The anode is fabricated by direct current (DC) reaction sputtering method. The cathode is fabricated by DC sputtering method or vacuum vaporization method. The organic films are deposited by spin-casting method. Finally, the relatively stable OLED with maximum luminance of 18.8cd/m2 emitting green color resulting from 8-tris-hydroxyquino-line aluminum (A1Q) is obtained.
Firstly, the effect of the ratio of poly-(N-vinylcarbazole) (PVK):A1Q: 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-l,3,4-oxadiazole (PBD) in emitting layer (EML) and PVK content in hole transport layer (HTL) on dual OLED property is discussed at the relatively invariable spin speed. The optimized contents of different organic materials are confirmed by comparing the observational luminance and stability of OLED with each other.
Then the effect of the Al cathode thickness and the ITO anode surface procession on OLED property is explored. The result shows that the optimized thickness of Al cathode can result in better luminance and stability, while the excessively thin or thick Al film will degenerate the property of OLED.
Next, the effect of the device structure on the property of OLED is discussed. The results show that the optimized dual-layer structure device is superior to the single-layer one, while inferior to the optimized three-layer one. The optimization of three-layer structure device is also discussed.
The effect of different deposition methods of Al cathode is also studied novelly. It
shows that the optimized dual-layer device with Al cathode deposited by the vacuum vaporization method has lower dark electric current and luminescence turn-on voltage than that deposited by DC magnetron sputtering method. The mechanism of these phenomena is discussed in detail.
本文鉴于高分子聚合物在稳定性方面所特有的优势，研制了高分子聚合物掺杂小分子荧光材料的OLED。采用直流磁控反应溅射法沉积阳极ITO薄膜，旋涂法沉积有机膜，直流磁控溅射法或真空蒸镀法沉积Al阴极，制备了8-羟基喹啉铝(AlQ)绿色OLED。并在此基础上对一些制备参数进行优化，得到最大发光亮度为18.8cd／m~2的OLED。
本文首先探讨了在转速固定的情况下双层结构器件中空穴传输层PVK含量以及发光层中聚乙烯基咔唑(PVK)、AIQ和2-(4-联苯基)-5-(4-丁基苯基)-1，3，4-噁二唑(PBD)各物质配比对器件性能的影响，通过观察和比较器件的亮度、稳定性，确定了空穴传输层和发光层中各种物质的最佳含量。
本文还研究了Al阴极厚度和ITO阳极表面处理对器件性能的影响。实验结果表明：Al阴极存在最佳厚度使OLED的发光亮度和稳定性达到最优化；ITO阳极表面处理改变了薄膜表面形貌，提高了OLED的亮度、稳定性和流明效率。
再者，本文研究了器件结构对OLED性能的影响。实验结果表明，单层结构器件性能最差，双层结构器件性能次之，三层结构器件性能最佳。论文还探讨了三层结构器件性能的优化。
本文的创新之处在于：具体探讨了真空蒸镀法和直流磁控溅射法沉积Al阴极对双层器件性能的影响，并对造成这种差异的原因进行了具体分析和探讨。
Organic light-emitting diodes (OLED) have become a shining star in the electronic display field since the end of the 1980s. This technology exhibits bright prospect in photoelectricity field due to its advantages of low DC drive voltage, active luminescence, excellent hue saturation, wide visual angle, etc. Nowadays, small-area OLED have been commercially produced in the area of mobile meters, screens of mobile phones and digital cameras, etc. However, some problems, especially on stability and lifetime, still need to resolve.
In respect of the excellent stability of polymer, the OLED using polymer doped with small molecular materials is fabricated. The anode is fabricated by direct current (DC) reaction sputtering method. The cathode is fabricated by DC sputtering method or vacuum vaporization method. The organic films are deposited by spin-casting method. Finally, the relatively stable OLED with maximum luminance of 18.8cd/m2 emitting green color resulting from 8-tris-hydroxyquino-line aluminum (A1Q) is obtained.
Firstly, the effect of the ratio of poly-(N-vinylcarbazole) (PVK):A1Q: 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-l,3,4-oxadiazole (PBD) in emitting layer (EML) and PVK content in hole transport layer (HTL) on dual OLED property is discussed at the relatively invariable spin speed. The optimized contents of different organic materials are confirmed by comparing the observational luminance and stability of OLED with each other.
Then the effect of the Al cathode thickness and the ITO anode surface procession on OLED property is explored. The result shows that the optimized thickness of Al cathode can result in better luminance and stability, while the excessively thin or thick Al film will degenerate the property of OLED.
Next, the effect of the device structure on the property of OLED is discussed. The results show that the optimized dual-layer structure device is superior to the single-layer one, while inferior to the optimized three-layer one. The optimization of three-layer structure device is also discussed.
The effect of different deposition methods of Al cathode is also studied novelly. It
shows that the optimized dual-layer device with Al cathode deposited by the vacuum vaporization method has lower dark electric current and luminescence turn-on voltage than that deposited by DC magnetron sputtering method. The mechanism of these phenomena is discussed in detail.
引文
[1] 田民波．电子显示．北京：清华大学出版社，2001，1～226．
[2] 黄春辉，李富有，黄岩谊．光电功能超薄膜．北京：北京大学出版社，2001，1～297．
[3] 白木，子荫．新一代OLED显示技术．现代显示．2002，33：14～17．
[4] C.W.Tang and S.A.VanSlyke. Organic electroluminescent diodes. Appl. Phys. Lett. 1987, 51 (12): 913～915.
[5] C.Adachi, S.Tokito, T.Tsutsui ,et al. Electroluminescence in organic films with three-layer structure. Jpn. J. Appl. Phys. Part 2, 1988, L269～L271.
[6] C.Adachi, S.Tokito, T.Tsutsui ,et al. Organic electroluminescent device with a three-layer structure. Jpn. J. Appl. Phys. Part 2, 1988, L713～L715.
[7] J.H.Burroughs, D.D.C.Bradley, A.R.Brown, et al. Nature, 1990,347.
[8] J.Kido, K.Hongawa, K.Okuyama, et al. White light-emitting organic electroluminescent devices using the poly (N-vinylcarbazole) emitter layer doped with three fluorescent dyes. Appl. Phys. Lett. 1994, 64(7): 815～817.
[9] J.Thompson, R.I.R.Blyth, M.Mazzeo, et al. White light emission from blends of blue-emitting organic molecules: A general route to the white organic light-emitting diode? Appl. Phys. Lett. 2001, 79(5): 560～562.
[10] C.J.Liang, D.Zhao, Z.R.Hong, et al. Improved performance of electroluminescent devices based on an europium complex. Appl. Phys. Lett. 2000, 76(1): 67～69.
[11] Y.Wang, N.Herron, V.V.Grushin, et al. Highly efficient electroluminescent materials based on fluorinated organometallic iridium compounds. Appl. Phys. Lett. 2001, 79(4): 449～451.
[12] X.C.Gao, Hong Cao, Chunhui,Huang, et al. Electroluminescence of a novel terbium complex. Appl. Phys. Lett. 1998, 72(18): 2217～2219.
[13] Noriyuki Takada, Tetsuo Tsutsui, and Shogo Saito. Control of emission characteristics in organic thin-film electroluminescent diodes using an optical-microcavity structure. Appl. Phys. Lett. 1993, 63 (15) : 2032～2034.
[14] Vera Cimrova and Dieter Neger. Microcavity effects in single-layer light-emitting devices based on poly(p-phenylene vinylene). J. Appl. Phys. 1996, 79 (6) : 3299～3306.
[15] M.Suzuki, H.Yokoyama, S.D.Brorson, et al. Observation of spontaneous emission lifetime
change of dye-containing Langmuir-Blodgett films in optical microcavities. Appl. Phys. Lett. 1991,58 (10) : 998～1000.
[16] A.Dodabalapur, L.J.Rothberg, T.M.Miller, et al. Microcavity effects in organic semiconductors. Appl. Phys. Lett. 1994, 64(19):2486～2488.
[17] U.Lemmer, R.Hennig,W.Guss, A.Ochse, et al. Microcavity effects in a spin-coated polymer two-layer system. Appl. Phys. Lett. 1995, 66(11) :1301～1303.
[18] Shizuo Tokito, Koji Noda, and Yasunori Taga. Strongly directed single mode emission from organic electroluminescent diode with a microcavity. Appl. Phys. Lett. 1996,68 (19) :2633～2635.
[19] Takahiro Nakayar(?)a, Yuzo Itoh, and Atsushi Kakuta. Organic photo-and electroluminescent devices with double mirrors. Appl. Phys. Lett. 1993, 63 (5): 594～596.
[20] C.Hosokawa, M.Eida, M.Matsuura, et al. Synth. Met. 1997,91.
[21] Y.Tududa, T.Watanabe, T.Wakimoto, et al. Synth. Met. 2000,111～112.
[22] Junji kido and Yasuhiro lizumi. Fabrication of highly efficient organic electroluminescent devices. Appl. Phys. Lett. 1998, 73 (19) : 2721～2723.
[23] 樊美公等．光化学基本原理与光子学材料科学．北京：科学出版社，2001，342～366．
[24] 刘祖刚，唐春玖，赵伟明等．有机薄膜电致发光器件的光学微腔效应．光学学报，1998，18(6)：793～798．
[25] H.Kim, J.S.Horwitz, G.P.Kushto, et al. Indium tin oxide thin film grown on flexible plastic substrates by pulsed-laser deposition for organic light-emitting diodes. Appl. Phys. Lett. 2001, 79 (3) :284～286.
[26] Hass G, Francombe H, Hoffmann W. Physics of Thin Films. New York: Academic Press, 1977.
[27] Radhouane Bei Hadj,Takayuki Ban,Yutaka Ohya. Electronic transport in tin-doped indium oxide thin films prepared by sol-gel technique. Journal of Applied Physics. 1998, 83 (4) :2139～2141.
[28] Carl K, Schmitt H, Friedrich I. Optimization of sputtered ITO films with respect to the oxygen partial pressure and substrate temperature. Thin Solid Films. 1997,295:151～155.
[29] 陈猛，白雪冬，黄荣芳．In_2O_3：Sn和ZnO：Al透明导电薄膜的结构及其导电机制．半导体学 报．2000，21(4)：394～399．
[30] 范志新．液晶器件工艺基础．北京：北京邮电大学出版社，2000，173～179．
[31] 田民波，刘德令．薄膜科学技术手册．北京：机械工业出版社，1991，263～447．
[32] 蒋雪茵，张志林，张步新等．稳定的光谱不随电流变化而变化的白色有机发光器件．发光学报．2002,23(2)：165～170．
[33] 黄剑，曹镛．有机电致发光材料研究进展．化工新型材料，2002，29(9)．
[35] 胡远川，王立铎，董桂芳等．肽青铜缓冲层改善有机电致发光器件性能的机理研究．功能材料，2002，33(3)：321～323．
[36] 朱文清，郑新友，张步新等．用C60为空穴缓冲层的高效有机电致发光器件．发光学报，23(3)：269～272．
[37] G.E.Jabbour, Y.Kawabe, S.E.Shaheen, et al. Highly efficient and bright organic electroluminescent devices with an aluminum cathode. Appl. Phys. Lett. 1997, 71(13):1762～1764.
[38] H.Tang, F.Li, and J.Shinar. Bright high efficiency blue organic light-emitting diodes with Al_2O_3/Al cathodes.
[39] T.(?)sterg(?)rd, A.J.Pal, H.Stubb. The role of interfaces in polymeric light-emitting diodes. Journal of Applied Physics.1998,83 (4):2338～22342.
[40] C.Hong, H.B.Chae, K.H.Lee, et al. The possibility of pulsed laser deposited organic thin films for light-emitting diodes. Thin Solid Films. 2002, 409:37～42.
[41] Hiroyuki Suzuki. Fabrication of electron injecting Mg:Ag alloy electrodes for organic light-emitting diodes with radio frequency magnetron sputter deposition. Appl. Phys. Lett. 1996, 69(11): 1611～1613.
[42] Feng Li, Jing Feng, Gang Cheng, et al. Electron injection and electroluminescence investigation of organic light-emitting devices based on a Sn/Al cathode. Synth. Met. 2002,126:347～350.
[43] Junji Kido, Toshio Matsumoto. Bright organic electroluminescent devices having a metal-doped electron-injecting layer. Appl. Phys. Lett. 1998, 73 (20) : 2866～2868.
[44] Hiroyuki Suzuki, Makoto Hikita. Organic light-emitting diodes with radio frequency sputter-deposited electron injecting electrodes. Appl. Phys. Lett. 1996, 68 (16): 2276～2278.
[45] L.S.Huang. Efficient and stable organic light-emitting diodes with a sputter-deposited cathode. Thin Solid Films. 2000, 363:47～50.
[46] P.E.Burrows, V.Bulovic, S.R.Forrest, et al. Reliability and degradation of organic light emitting devices. Appl. Phys. Lett. 1994, 66 (23): 2922～2924.
[47] 雷玉堂，王庆有，何加铭等．光电检测技术．北京：中国计量出版社，92～96．
[48] 李文连．有机电致发光的效率．液晶与显示，2001，16(2)：120～123．
[49] J.Laubender, L.Chkoda, M.Sokolowski, et al. The influence of oxygen and air on the characteristics of organic light-emitting decices studied by in vacuo measurements. Synt. Met. 2000,111-112:373～376.
[50] Masahiko Ishii, Yasunori taga. Influence of temperature and drive current on degradation mechanisms in organic light-emitting diodes. Appl. Phys. Lett. 2002, 80 (18): 3430～3432.
[51] 张兴义．电子显示技术．北京：北京理工大学出版社，1995，17～39．
[52] 刘恩科，朱秉升，罗晋生．半导体物理学．北京：国防工业出版社，1994，84～86．
[53] 马礼敦．高等结构分析．上海：复旦大学出版社，2001，426～432．
[54] 罗庆尧，邓延倬，蔡汝秀等．分光光度计．北京：科学出版社，1998，87～160．
[55] 李文连．有机LED的界面与载流子注入．液晶与显示，1998，13(3)：203～207．
[56] 候晶莹，高文宝，孙家鑫等．利用有机层间互相掺杂提高有机电致发光器件的效率．发光学报，2003，24(2)：157～160．
[57] C.EMadigan, M.H.Lu, and J.C.Sturm. Improvement of output coupling efficiency of organic light-emitting diodes by backside substrate modification. Appl. Phys. Lett. 2000, 76 (13) :1650～1652.
[58] Takashi Yamasaki, Kazuhiro Sumioka, and Tetsuo Tsutsui. Organic light-emitting device with an ordered monolayer of silica microspheres as a scattering medium. Appl. Phys. Lett. 2000, 76 (10) :1243～1245.
[59] 孙刚，李文连，赵宇等．具有纯Tb3+发光光谱的有机电致发光二极管．光学学报， 1997,17(2)：166～170．
[60] Y. Shi, J. Liu and Y. Yang. Device performance and Polyer morphology in polyer light emitting diodes: The control of thin film morphology and device quantum efficiency. Journal of Applied Physics,2000, 88(2): 4254～4263.
[61] Jie Liu, Yijian Shi, Liping Ma, and Yang Yang. Device performance and Polyer morphology in polyer light emitting diodes: The control of device electrical properties and metal/polymer contact. Journal of Applied Physics,2000, 88(2): 605～609.
[62] Jie Liu, Yijian Shi and Yang Yang. Improving performance and of polymer light-emitting diodes using polymer solid solutions. Appl. Phys. Lett., 2001, 79 (5):578-580.
[63] F.Li, H.Tang, J.Anderegg, et ai. Fabrication and electroluminescence of double-layered organic light-emitting diodes with the Al_2O_3/Al cathode. Appl. Phys. Lett. 1997, 70(10):1233～1235.
[2] 黄春辉，李富有，黄岩谊．光电功能超薄膜．北京：北京大学出版社，2001，1～297．
[3] 白木，子荫．新一代OLED显示技术．现代显示．2002，33：14～17．
[4] C.W.Tang and S.A.VanSlyke. Organic electroluminescent diodes. Appl. Phys. Lett. 1987, 51 (12): 913～915.
[5] C.Adachi, S.Tokito, T.Tsutsui ,et al. Electroluminescence in organic films with three-layer structure. Jpn. J. Appl. Phys. Part 2, 1988, L269～L271.
[6] C.Adachi, S.Tokito, T.Tsutsui ,et al. Organic electroluminescent device with a three-layer structure. Jpn. J. Appl. Phys. Part 2, 1988, L713～L715.
[7] J.H.Burroughs, D.D.C.Bradley, A.R.Brown, et al. Nature, 1990,347.
[8] J.Kido, K.Hongawa, K.Okuyama, et al. White light-emitting organic electroluminescent devices using the poly (N-vinylcarbazole) emitter layer doped with three fluorescent dyes. Appl. Phys. Lett. 1994, 64(7): 815～817.
[9] J.Thompson, R.I.R.Blyth, M.Mazzeo, et al. White light emission from blends of blue-emitting organic molecules: A general route to the white organic light-emitting diode? Appl. Phys. Lett. 2001, 79(5): 560～562.
[10] C.J.Liang, D.Zhao, Z.R.Hong, et al. Improved performance of electroluminescent devices based on an europium complex. Appl. Phys. Lett. 2000, 76(1): 67～69.
[11] Y.Wang, N.Herron, V.V.Grushin, et al. Highly efficient electroluminescent materials based on fluorinated organometallic iridium compounds. Appl. Phys. Lett. 2001, 79(4): 449～451.
[12] X.C.Gao, Hong Cao, Chunhui,Huang, et al. Electroluminescence of a novel terbium complex. Appl. Phys. Lett. 1998, 72(18): 2217～2219.
[13] Noriyuki Takada, Tetsuo Tsutsui, and Shogo Saito. Control of emission characteristics in organic thin-film electroluminescent diodes using an optical-microcavity structure. Appl. Phys. Lett. 1993, 63 (15) : 2032～2034.
[14] Vera Cimrova and Dieter Neger. Microcavity effects in single-layer light-emitting devices based on poly(p-phenylene vinylene). J. Appl. Phys. 1996, 79 (6) : 3299～3306.
[15] M.Suzuki, H.Yokoyama, S.D.Brorson, et al. Observation of spontaneous emission lifetime
change of dye-containing Langmuir-Blodgett films in optical microcavities. Appl. Phys. Lett. 1991,58 (10) : 998～1000.
[16] A.Dodabalapur, L.J.Rothberg, T.M.Miller, et al. Microcavity effects in organic semiconductors. Appl. Phys. Lett. 1994, 64(19):2486～2488.
[17] U.Lemmer, R.Hennig,W.Guss, A.Ochse, et al. Microcavity effects in a spin-coated polymer two-layer system. Appl. Phys. Lett. 1995, 66(11) :1301～1303.
[18] Shizuo Tokito, Koji Noda, and Yasunori Taga. Strongly directed single mode emission from organic electroluminescent diode with a microcavity. Appl. Phys. Lett. 1996,68 (19) :2633～2635.
[19] Takahiro Nakayar(?)a, Yuzo Itoh, and Atsushi Kakuta. Organic photo-and electroluminescent devices with double mirrors. Appl. Phys. Lett. 1993, 63 (5): 594～596.
[20] C.Hosokawa, M.Eida, M.Matsuura, et al. Synth. Met. 1997,91.
[21] Y.Tududa, T.Watanabe, T.Wakimoto, et al. Synth. Met. 2000,111～112.
[22] Junji kido and Yasuhiro lizumi. Fabrication of highly efficient organic electroluminescent devices. Appl. Phys. Lett. 1998, 73 (19) : 2721～2723.
[23] 樊美公等．光化学基本原理与光子学材料科学．北京：科学出版社，2001，342～366．
[24] 刘祖刚，唐春玖，赵伟明等．有机薄膜电致发光器件的光学微腔效应．光学学报，1998，18(6)：793～798．
[25] H.Kim, J.S.Horwitz, G.P.Kushto, et al. Indium tin oxide thin film grown on flexible plastic substrates by pulsed-laser deposition for organic light-emitting diodes. Appl. Phys. Lett. 2001, 79 (3) :284～286.
[26] Hass G, Francombe H, Hoffmann W. Physics of Thin Films. New York: Academic Press, 1977.
[27] Radhouane Bei Hadj,Takayuki Ban,Yutaka Ohya. Electronic transport in tin-doped indium oxide thin films prepared by sol-gel technique. Journal of Applied Physics. 1998, 83 (4) :2139～2141.
[28] Carl K, Schmitt H, Friedrich I. Optimization of sputtered ITO films with respect to the oxygen partial pressure and substrate temperature. Thin Solid Films. 1997,295:151～155.
[29] 陈猛，白雪冬，黄荣芳．In_2O_3：Sn和ZnO：Al透明导电薄膜的结构及其导电机制．半导体学 报．2000，21(4)：394～399．
[30] 范志新．液晶器件工艺基础．北京：北京邮电大学出版社，2000，173～179．
[31] 田民波，刘德令．薄膜科学技术手册．北京：机械工业出版社，1991，263～447．
[32] 蒋雪茵，张志林，张步新等．稳定的光谱不随电流变化而变化的白色有机发光器件．发光学报．2002,23(2)：165～170．
[33] 黄剑，曹镛．有机电致发光材料研究进展．化工新型材料，2002，29(9)．
[35] 胡远川，王立铎，董桂芳等．肽青铜缓冲层改善有机电致发光器件性能的机理研究．功能材料，2002，33(3)：321～323．
[36] 朱文清，郑新友，张步新等．用C60为空穴缓冲层的高效有机电致发光器件．发光学报，23(3)：269～272．
[37] G.E.Jabbour, Y.Kawabe, S.E.Shaheen, et al. Highly efficient and bright organic electroluminescent devices with an aluminum cathode. Appl. Phys. Lett. 1997, 71(13):1762～1764.
[38] H.Tang, F.Li, and J.Shinar. Bright high efficiency blue organic light-emitting diodes with Al_2O_3/Al cathodes.
[39] T.(?)sterg(?)rd, A.J.Pal, H.Stubb. The role of interfaces in polymeric light-emitting diodes. Journal of Applied Physics.1998,83 (4):2338～22342.
[40] C.Hong, H.B.Chae, K.H.Lee, et al. The possibility of pulsed laser deposited organic thin films for light-emitting diodes. Thin Solid Films. 2002, 409:37～42.
[41] Hiroyuki Suzuki. Fabrication of electron injecting Mg:Ag alloy electrodes for organic light-emitting diodes with radio frequency magnetron sputter deposition. Appl. Phys. Lett. 1996, 69(11): 1611～1613.
[42] Feng Li, Jing Feng, Gang Cheng, et al. Electron injection and electroluminescence investigation of organic light-emitting devices based on a Sn/Al cathode. Synth. Met. 2002,126:347～350.
[43] Junji Kido, Toshio Matsumoto. Bright organic electroluminescent devices having a metal-doped electron-injecting layer. Appl. Phys. Lett. 1998, 73 (20) : 2866～2868.
[44] Hiroyuki Suzuki, Makoto Hikita. Organic light-emitting diodes with radio frequency sputter-deposited electron injecting electrodes. Appl. Phys. Lett. 1996, 68 (16): 2276～2278.
[45] L.S.Huang. Efficient and stable organic light-emitting diodes with a sputter-deposited cathode. Thin Solid Films. 2000, 363:47～50.
[46] P.E.Burrows, V.Bulovic, S.R.Forrest, et al. Reliability and degradation of organic light emitting devices. Appl. Phys. Lett. 1994, 66 (23): 2922～2924.
[47] 雷玉堂，王庆有，何加铭等．光电检测技术．北京：中国计量出版社，92～96．
[48] 李文连．有机电致发光的效率．液晶与显示，2001，16(2)：120～123．
[49] J.Laubender, L.Chkoda, M.Sokolowski, et al. The influence of oxygen and air on the characteristics of organic light-emitting decices studied by in vacuo measurements. Synt. Met. 2000,111-112:373～376.
[50] Masahiko Ishii, Yasunori taga. Influence of temperature and drive current on degradation mechanisms in organic light-emitting diodes. Appl. Phys. Lett. 2002, 80 (18): 3430～3432.
[51] 张兴义．电子显示技术．北京：北京理工大学出版社，1995，17～39．
[52] 刘恩科，朱秉升，罗晋生．半导体物理学．北京：国防工业出版社，1994，84～86．
[53] 马礼敦．高等结构分析．上海：复旦大学出版社，2001，426～432．
[54] 罗庆尧，邓延倬，蔡汝秀等．分光光度计．北京：科学出版社，1998，87～160．
[55] 李文连．有机LED的界面与载流子注入．液晶与显示，1998，13(3)：203～207．
[56] 候晶莹，高文宝，孙家鑫等．利用有机层间互相掺杂提高有机电致发光器件的效率．发光学报，2003，24(2)：157～160．
[57] C.EMadigan, M.H.Lu, and J.C.Sturm. Improvement of output coupling efficiency of organic light-emitting diodes by backside substrate modification. Appl. Phys. Lett. 2000, 76 (13) :1650～1652.
[58] Takashi Yamasaki, Kazuhiro Sumioka, and Tetsuo Tsutsui. Organic light-emitting device with an ordered monolayer of silica microspheres as a scattering medium. Appl. Phys. Lett. 2000, 76 (10) :1243～1245.
[59] 孙刚，李文连，赵宇等．具有纯Tb3+发光光谱的有机电致发光二极管．光学学报， 1997,17(2)：166～170．
[60] Y. Shi, J. Liu and Y. Yang. Device performance and Polyer morphology in polyer light emitting diodes: The control of thin film morphology and device quantum efficiency. Journal of Applied Physics,2000, 88(2): 4254～4263.
[61] Jie Liu, Yijian Shi, Liping Ma, and Yang Yang. Device performance and Polyer morphology in polyer light emitting diodes: The control of device electrical properties and metal/polymer contact. Journal of Applied Physics,2000, 88(2): 605～609.
[62] Jie Liu, Yijian Shi and Yang Yang. Improving performance and of polymer light-emitting diodes using polymer solid solutions. Appl. Phys. Lett., 2001, 79 (5):578-580.
[63] F.Li, H.Tang, J.Anderegg, et ai. Fabrication and electroluminescence of double-layered organic light-emitting diodes with the Al_2O_3/Al cathode. Appl. Phys. Lett. 1997, 70(10):1233～1235.