有机电致发光器件性能改善研究
|
摘要
有机电致发光器件具有主动发光、成本低、厚度薄、响应速度快、重量轻、能耗低、高亮度、高效率、工作温度范围大、可以实现全色显示和柔性显示等优点,自从1987年Tang首次报道了工作在低电压下的高亮度有机电致发光器件(OLED)以来,作为一种新型的平板显示技术,OLED倍受科学界和产业界的重视。
在本论文的研究中,我们做了如下三方面的工作：
第一,由于有机发光器件存在诸多问题,如效率偏低,开启电压较高等。而器件的开启电压是表征器件的一个关键参数,降低开启电压是有机发光器件通向实用化阶段必须要解决的问题。目前,几乎所有的研究者都是利用对空穴注入层的P型掺杂手段来降低器件开启电压。P型掺杂工艺存在的缺点是其可重复性低,无法保证每次制得的器件具有相同的性能。在本文中,我们通过空穴传输层的设计,利用NPB/MoOx多层结构,有效的降低了器件的开启电压。多层结构的优点就是其容易控制,工艺简单,器件具有很高的可重复性。相比于普通结构器件,利用多层结构的空穴传输层的器件在1000cd/m2时的工作电压降低了0.8v。图1和图2为不同器件电流-电压及电压亮度特性的对比,图3为器件的归一化光谱(具体见论文第二章)。
第二,由于有机电致发光器件具有轻便,可柔性,低功耗等的特性,使其可以应用在一些特殊的用途,如建筑物的玻璃装饰、汽车风挡玻璃、天窗以及显示器件等。这就需要此种器件具有一定的透明度。我们对其进行了研究设计。通过利用微腔效应,我们制作了阳极和阴极具有完全相同结构的透明器件,电极结构为：Ag(20 nm)/Alq(85 nm)/Ag(20 nm)/Alq(85 nm),通过理论设计电极结构参数(本文中只对有机层Alq的厚度进行了调节),最终得到的器件两侧的发光效率、光谱及色坐标差别很小。图4为我们所设计的透明器件的结构示意图,从图中可以看出,除阳极一侧的玻璃外,器件的两电极具有完全相同的结构,这就保证了器件两侧的光谱,亮度及效率差别很小。我们通过理论和实验都讨论了这一结构器件的性能,理论和实验符合很好。图1(a)器件A, B, C, D,和E的电流-电压特性,(b)器件A, B, C, D,和E的亮度-电压特性图2(a)器件A,F,G和H的电流-电压特性,(b)器件A,F,G和H的亮度-电压特性图3器件A,F,G和H的归一化电致发光光谱图4透明器件的结构示意图
图5为利用多层薄膜电极(Device A)和ITO电极(Device B)制备的器件的法线发射光谱。从图中可以看出,利用两个周期的多层薄膜电极制备的器件具有较强的微腔效应,器件光谱有两个共振峰,且每个共振峰都有明显的窄化现象。另外,Device A两侧电极的出射光谱差别很小。图6a为Device A的阴极一侧不同观察角度的发射光谱,随着观察角度的增加,光谱共振峰发生蓝移。图6b为Device A的阳极一侧不同观察角度的发射光谱,其变化趋势与阴极一侧的光谱变化趋势相同。
第三,柔性衬底作为器件的衬底,最终应用在照明和显示上,这是有机电致发光器件一个极其重要的应用方向。目前熟知的透明电极ITO,其在可见光区具有很好的透过率,但是其应用在低成本、大面积柔性衬底上存在很多问题。如,地球上铟的含量很少,这使得ITO成本较高；ITO本身较脆,需要高的生长温度以及一些特殊的工艺处理；铟离子的扩散特性也不利于长寿命器件的制备等。针对以上原因,我们研究设计了利用金属氧化物和金属银结合的多层电极,其在可见光范围的透射率与ITO相比相差不大,而其电阻和柔韧性要远好于ITO电极。图5透明器件的结构示意图图6a透明器件的结构示意图
图7为MAM多层薄膜及ITO的透射谱,从图中可以看出,在可见光范围内,多层薄膜电极具有较高透过率(平均透过率大于84%),这一透过率很接近ITO的透过率,这就使得我们可以利用这种薄膜电极来制备无微腔效应有机电致发光器件。图8为我们利用该电极在柔性衬底PET上制备白光器件的发射光谱。图7MoOx/Ag/MoOx多层薄膜电极及ITO的透射光谱图8利用MoOx/Ag/MoOx多层薄膜电极制备的白光器件的发射光谱
Organic light emitting devices(OLEDs) have some advantages, such an active emitting, low cost, light weight, low power consumption, high luminance, high efficiency, operating within large temperature region, being able to achieve full color and flexible display, and so on. Since C. W. Tang reported OLEDs with high luminance and low operating voltage, the OLEDs as a new technology for planar display were paid much attention to by academia and industry.
In this paper, we introduced our work as follows: Firstly, because the OLEDs have some disadvantages, such as, low efficiency and high turn-on voltage, and so on. The turn-on voltage is a key parameter to describe the performance of the devices. In order to apply the OLEDs in practice, we must low the turn-on voltage. At present, P-doped hole transport layer is used abroad to reduce the turn-on voltage of the OLEDs. The disadvantage of P-doped hole transport layer is the complex processing and the repeatability is bad. In our paper, we used multi-layer NPB/MoOx/NPB as hole transport layer to efficiently reduce the turn-on voltage of the device. The advantage of multi-layer NPB/MoOx/NPB for hole transport layer is easy process to fabricated the devices. The driving voltage of tris(8-hydroxyquinoline) aluminum (Alq3)-based organic light-emitting devices (OLEDs) could be lowered by 0.8V at 1000cd/m2 by using multiple structure of NPB/MoO3/NPB. Figure 1(a) and (b) shows the voltage-current density and voltage-luminance characteristics of the devices and figure 3 showed the normalized EL intensity of the devices(details are shown in the second chapter of our paper).
The electrode consist of Ag(20 nm)/Alq(85 nm)/Ag(20 nm)/Alq(85 nm) and we obtained the same spectra, efficiency, and color coordinates for the both sides of the devices by adjusting the parameter of the electrodes. Figure 4 shows the structure of the semitransparent device. As can be seen, the cathode and anode have the same Fig.1(a) The voltage-current density Fig.1(b) The voltage-luminance curve of curve of device A, B, C, D, and E device A, B, C, D, and E Fig.2(a) The voltage-current density Fig.2(b) The voltage-luminance curve of device A,F,G,and H curve of device A, F, G, and H.
Fig.3 The normalized EL intensity of devices A, F, G, and H. Fig.4 The structure of the semitransparent device structure except for the additional glass for the anode, which makes the very little difference for the spectra, luminance and efficiency between the two sides of the device.
Figure 5 shows the normal spectra of the devices A and B. As can be seen, the device with two periods electrodes has stong microcavity effect. Device A have two resonant emission peaks and we also can see that the narrowness of the full width at half maximum of the DPVBi and (F-BT)2Ir(acac) emission in device A is observed. is observed. There is only a little difference between the sides of the device for the spectra. Figure 6a shows the spectra from the cathode side of the device A at different viewing degree. With increasing viewing angle, the peak wavelength shifts to a shorter wavelength due to the microcavity effect in the device. Figure 6b shows the spectra from the anode side of the device A at different viewing degree, which has the same trend to that of cathode side. Fig.5 The structure of the semitransparent device Fig.6a The structure of the semitransparent device Fig.6b The structure of the semitransparent device
Finally, flexible display and light device with OLEDs technology is one of the very important applications. The currently used indium tin oxide (ITO) has significant shortcomings for low-cost, large-area, and flexible device applications that include rising cost of indium, brittleness, need for high growth temperature and special technology, and the diffusion nature of indium ions which is harmful to the long-term performance of OLEDs.
Figure 7 shows the measured and calculated optical transmittance curves of multilayer MAM as a function of the wavelength in visible region. The measured optical transmittance curve of ITO was also plotted in Fig.1. It can be seen that a high average transmittance of over 84% is obtained for the MAM-based transparent multilayer, which is comparable with the conventional ITO. So we can fabricate the nonmicrocavity OLEDs with the MAM anode. The spectra of the white light OLEDs with MAM anode is shown in figure 8. Fig.7 The structure of the semitransparent device Fig.8 The structure of the semitransparent device
在本论文的研究中,我们做了如下三方面的工作：
第一,由于有机发光器件存在诸多问题,如效率偏低,开启电压较高等。而器件的开启电压是表征器件的一个关键参数,降低开启电压是有机发光器件通向实用化阶段必须要解决的问题。目前,几乎所有的研究者都是利用对空穴注入层的P型掺杂手段来降低器件开启电压。P型掺杂工艺存在的缺点是其可重复性低,无法保证每次制得的器件具有相同的性能。在本文中,我们通过空穴传输层的设计,利用NPB/MoOx多层结构,有效的降低了器件的开启电压。多层结构的优点就是其容易控制,工艺简单,器件具有很高的可重复性。相比于普通结构器件,利用多层结构的空穴传输层的器件在1000cd/m2时的工作电压降低了0.8v。图1和图2为不同器件电流-电压及电压亮度特性的对比,图3为器件的归一化光谱(具体见论文第二章)。
第二,由于有机电致发光器件具有轻便,可柔性,低功耗等的特性,使其可以应用在一些特殊的用途,如建筑物的玻璃装饰、汽车风挡玻璃、天窗以及显示器件等。这就需要此种器件具有一定的透明度。我们对其进行了研究设计。通过利用微腔效应,我们制作了阳极和阴极具有完全相同结构的透明器件,电极结构为：Ag(20 nm)/Alq(85 nm)/Ag(20 nm)/Alq(85 nm),通过理论设计电极结构参数(本文中只对有机层Alq的厚度进行了调节),最终得到的器件两侧的发光效率、光谱及色坐标差别很小。图4为我们所设计的透明器件的结构示意图,从图中可以看出,除阳极一侧的玻璃外,器件的两电极具有完全相同的结构,这就保证了器件两侧的光谱,亮度及效率差别很小。我们通过理论和实验都讨论了这一结构器件的性能,理论和实验符合很好。图1(a)器件A, B, C, D,和E的电流-电压特性,(b)器件A, B, C, D,和E的亮度-电压特性图2(a)器件A,F,G和H的电流-电压特性,(b)器件A,F,G和H的亮度-电压特性图3器件A,F,G和H的归一化电致发光光谱图4透明器件的结构示意图
图5为利用多层薄膜电极(Device A)和ITO电极(Device B)制备的器件的法线发射光谱。从图中可以看出,利用两个周期的多层薄膜电极制备的器件具有较强的微腔效应,器件光谱有两个共振峰,且每个共振峰都有明显的窄化现象。另外,Device A两侧电极的出射光谱差别很小。图6a为Device A的阴极一侧不同观察角度的发射光谱,随着观察角度的增加,光谱共振峰发生蓝移。图6b为Device A的阳极一侧不同观察角度的发射光谱,其变化趋势与阴极一侧的光谱变化趋势相同。
第三,柔性衬底作为器件的衬底,最终应用在照明和显示上,这是有机电致发光器件一个极其重要的应用方向。目前熟知的透明电极ITO,其在可见光区具有很好的透过率,但是其应用在低成本、大面积柔性衬底上存在很多问题。如,地球上铟的含量很少,这使得ITO成本较高；ITO本身较脆,需要高的生长温度以及一些特殊的工艺处理；铟离子的扩散特性也不利于长寿命器件的制备等。针对以上原因,我们研究设计了利用金属氧化物和金属银结合的多层电极,其在可见光范围的透射率与ITO相比相差不大,而其电阻和柔韧性要远好于ITO电极。图5透明器件的结构示意图图6a透明器件的结构示意图
图7为MAM多层薄膜及ITO的透射谱,从图中可以看出,在可见光范围内,多层薄膜电极具有较高透过率(平均透过率大于84%),这一透过率很接近ITO的透过率,这就使得我们可以利用这种薄膜电极来制备无微腔效应有机电致发光器件。图8为我们利用该电极在柔性衬底PET上制备白光器件的发射光谱。图7MoOx/Ag/MoOx多层薄膜电极及ITO的透射光谱图8利用MoOx/Ag/MoOx多层薄膜电极制备的白光器件的发射光谱
Organic light emitting devices(OLEDs) have some advantages, such an active emitting, low cost, light weight, low power consumption, high luminance, high efficiency, operating within large temperature region, being able to achieve full color and flexible display, and so on. Since C. W. Tang reported OLEDs with high luminance and low operating voltage, the OLEDs as a new technology for planar display were paid much attention to by academia and industry.
In this paper, we introduced our work as follows: Firstly, because the OLEDs have some disadvantages, such as, low efficiency and high turn-on voltage, and so on. The turn-on voltage is a key parameter to describe the performance of the devices. In order to apply the OLEDs in practice, we must low the turn-on voltage. At present, P-doped hole transport layer is used abroad to reduce the turn-on voltage of the OLEDs. The disadvantage of P-doped hole transport layer is the complex processing and the repeatability is bad. In our paper, we used multi-layer NPB/MoOx/NPB as hole transport layer to efficiently reduce the turn-on voltage of the device. The advantage of multi-layer NPB/MoOx/NPB for hole transport layer is easy process to fabricated the devices. The driving voltage of tris(8-hydroxyquinoline) aluminum (Alq3)-based organic light-emitting devices (OLEDs) could be lowered by 0.8V at 1000cd/m2 by using multiple structure of NPB/MoO3/NPB. Figure 1(a) and (b) shows the voltage-current density and voltage-luminance characteristics of the devices and figure 3 showed the normalized EL intensity of the devices(details are shown in the second chapter of our paper).
The electrode consist of Ag(20 nm)/Alq(85 nm)/Ag(20 nm)/Alq(85 nm) and we obtained the same spectra, efficiency, and color coordinates for the both sides of the devices by adjusting the parameter of the electrodes. Figure 4 shows the structure of the semitransparent device. As can be seen, the cathode and anode have the same Fig.1(a) The voltage-current density Fig.1(b) The voltage-luminance curve of curve of device A, B, C, D, and E device A, B, C, D, and E Fig.2(a) The voltage-current density Fig.2(b) The voltage-luminance curve of device A,F,G,and H curve of device A, F, G, and H.
Fig.3 The normalized EL intensity of devices A, F, G, and H. Fig.4 The structure of the semitransparent device structure except for the additional glass for the anode, which makes the very little difference for the spectra, luminance and efficiency between the two sides of the device.
Figure 5 shows the normal spectra of the devices A and B. As can be seen, the device with two periods electrodes has stong microcavity effect. Device A have two resonant emission peaks and we also can see that the narrowness of the full width at half maximum of the DPVBi and (F-BT)2Ir(acac) emission in device A is observed. is observed. There is only a little difference between the sides of the device for the spectra. Figure 6a shows the spectra from the cathode side of the device A at different viewing degree. With increasing viewing angle, the peak wavelength shifts to a shorter wavelength due to the microcavity effect in the device. Figure 6b shows the spectra from the anode side of the device A at different viewing degree, which has the same trend to that of cathode side. Fig.5 The structure of the semitransparent device Fig.6a The structure of the semitransparent device Fig.6b The structure of the semitransparent device
Finally, flexible display and light device with OLEDs technology is one of the very important applications. The currently used indium tin oxide (ITO) has significant shortcomings for low-cost, large-area, and flexible device applications that include rising cost of indium, brittleness, need for high growth temperature and special technology, and the diffusion nature of indium ions which is harmful to the long-term performance of OLEDs.
Figure 7 shows the measured and calculated optical transmittance curves of multilayer MAM as a function of the wavelength in visible region. The measured optical transmittance curve of ITO was also plotted in Fig.1. It can be seen that a high average transmittance of over 84% is obtained for the MAM-based transparent multilayer, which is comparable with the conventional ITO. So we can fabricate the nonmicrocavity OLEDs with the MAM anode. The spectra of the white light OLEDs with MAM anode is shown in figure 8. Fig.7 The structure of the semitransparent device Fig.8 The structure of the semitransparent device
引文
[1]Pope M, Kallmann H, Magnante P J.Electroluminescence in organic crystals[J]. J. Chem. Phys.1963,38:2042-2043.
[2]Helfrich W, Schneider W G.Recombination radiation in anthracene crystals[J]. Phys. Rev. Lett.1965,14:229-231.
[3]Lohmann F, Mehl W.Dark injection and radiative recombination of electrons and holes in naphthalene crystals[J]. J. Chem. Phys.1969,50:500-506.
[4]Williams D M, Schadt M.A simple organic electroluminescence diode[J]. Proc. IEEE, 1970,58:476-476.
[5]Vincett P S, Barlow W A, Hann R A, Roberts G B. Electrical conduction and low voltage blue electroluminescene in vacuum-deposited organic films[J]. Thin Solid Films 1982 94:171-183.
[6]S. A. Vanslyke, C. W. Tang. Organic electroluminescent devices having improved power conversion efficiencies:U. S.4539507 [P] 1985-9-3.
[7]Tang C W, Vanslyke S A.Organic electroluminescent diodes[J]. Appl. Phys. Lett. 1987,51:913-915.
[8]Adachi C, Tolito S, Tsutsui T, Saito S. Organic electroluminescent devices with a Three-layer structure, Jpn. J. Appl. Phys.1988,27:L713-L715.
[9]Adachi C, Tolito S, Tsutsui T, Saito S. Electroluminescence in organic films with a Three-layer structure[J]. Jpn. J. Appl. Phys. (1988) 27:L269-L271.
[10]M.-H. Lu, M. S. Weaver, T. X. Zhou, M. Rothman, R. C. Kwong, M. Hack, J. J. Brown, High-efficiency top-emitting organic light-emitting devices, Appl. Phys. Lett. (2002) 81, 3921.
[11]H. W. Choi, S. Y. Kim, K.-B. Kim, Y. H. Tak, J.-L. Lee, Enhancement of hole injection using O2 plasma-treated Ag anode for top-emitting organic light-emitting diodes, Appl. Phys. Lett. (2005)86,012104.
[12]H. Kanno,Y. Sun, S. R. Forrest, High-efficiency top-emissive white-light-emitting organic electrophosphorescent devices, Appl. Phys. Lett. (2005) 86,263502.
[13]H.-K. Kim, D.-G. Kim, K.-S. Lee, M.-S. Huh, S. H. Jeong, K. I. Kim, H. Kim, D. W. Han, J. H. Kwon, Plasma damage-free deposition of Al cathode on organic light-emitting devices by using mirror shape target sputtering, Appl. Phys. Lett. (2004) 85,4295.
[14]H.-K. Kim, K.-S. Lee, J. H. Kwon, Transparent indium zinc oxide top cathode prepared by plasma damage-free sputtering for top-emitting organic light-emitting diodes, Appl. Phys. Lett. (2006)88,012103.
[15]H. Riel, S. Karg, T. Beierlein, B. Ruhstaller, W. Rieβ, Phosphorescent top-emitting organic light-emitting devices with improved light outcoupling, Appl. Phys. Lett. (2003) 82,466.
[16]S. Han, X. Feng, Z. H. Lu, D. Johnson, R. Wood, Transparent-cathode for top-emission organic light-emitting diodes, Appl. Phys. Lett. (2003) 82,2715.
[17]S. F. Hsu, C.-C. Lee, A. T. Hu, C. H. Chen, Fabrication of blue top-emitting organic light-emitting devices with highly saturated color, Current Applied Physics (2004) 4,663.
[18]C. J. Lee, R. B. Pode, D. G. Moon, J. I. Han, N. H. Park, S. H. Baik, S. S. Ju, On the problem of microcavity effects on the top emitting OLED with semi-transparent metal cathode, Phys. Stat. Sol. (a) (2004) 201,1022.
[19]D. G. Moon, R. B. Pode, C. J. Lee, J. I. Han, Transient electro-phosphorescence in red top-emitting organic light-emitting devices, Appl. Phys. Lett. (2004) 85,4771.
[20]R. B. Pode, C. J. Lee, D. G. Moon, J. I. Han, Transparent conducting metal electrode for top emission organic light-emitting devices:Ca-Ag double layer, Appl. Phys. Lett. (2004) 84,4614.
[21]D.G. Moon, R.B. Pode, C.J. Lee, J.I. Han, Efficient red electro-phosphorescent top-emitting organic light-emitting devices, Materials Science and Engineering B 121 (2005) 232.
[22]S.-F. Hsu, C.-C. Lee, S.-W. Hwang, H.-H. Chen, C. H. Chena, A. T. Hu, Color-saturated and highly efficient top-emitting organic light-emitting devices, Thin Solid Films (2005) 478,271.
[23]Y Li, L.-W. Tan, X.-T. Hao, K. S. Ong, F. Zhu, L.-S. Hung, Flexible top-emitting electroluminescent devices on polyethylene terephthalate substrates, Appl. Phys. Lett. (2005) 86,153508.
[24]S.-F. Hsu, C.-C. Lee, S.-W. Hwang, H.-H. Chen, Highly efficient top-emitting white organic electroluminescent devices, Appl. Phys. Lett. (2005) 86,253508.
[25]B. Xiao, B. Yao, C. Ma, S. Liu, Z. Xie, L. Wang, Highly efficient top-emitting organic light-emitting devices with aluminium electrodes, Semicond. Sci. Technol. (2005) 20, 952.
[26]C.-W. Chen, P.-Y. Hsieh, H.-H. Chiang, C.-L. Lin, H.-M. Wu, C.-C. Wu, Top-emitting organic light-emitting devices using surface-modified Ag anode, Appl. Phys. Lett. (2003) 83,5127.
[27]Y. Q. Li, J.X. Tang, Z.Y. Xie, L.S. Hung, S.S. Lau, An efficient organic light-emitting diode with silver electrodes, Chem. Phys. Lett. (2004) 386,128.
[28]C.-C. Wu, C.-L. Lin, P.-Y. Hsieh, H.-H. Chiang, Methodology for optimizing viewing characteristics of top-emitting organic light-emitting devices, Appl. Phys. Lett. (2004) 84, 3966.
[29]C.-L. Lin, H.-W. Lin, C.-C. Wu, Examining microcavity organic light-emitting devices having two metal mirrors, Appl. Phys. Lett. (2005) 87,021101.
[30]C.-J. Yang, C.-L. Lin, C.-C. Wu, High-contrast top-emitting organic light-emitting devices for active-matrix displays, Appl. Phys. Lett. (2005) 87,143507.
[31]H. Peng, J. Sun, X. Zhu, X. Yu, M. Wong, H.-S. Kwok, High-efficiency microcavity top-emitting organic light-emitting diodes using silver anode, Appl. Phys. Lett. (2006) 88, 073517.
[32]X. Y. Deng, M. K. Ho, and K. Y. Wong, Top-emitting polymer light-emitting diodes with environmentally stable cathodes, J. Appl. Phys. (2006) 99,016103.
[33]J. Y. Lee, Efficient hole injection in organic light-emitting diodes using C60 as a buffer layer for Al reflective anodes, Appl. Phys. Lett. (2006) 88,073512.
[34]B. D. Lee, Y.-H. Cho, W.-J. Kim, M. H. Oh, J. H. Lee, D. S. Zang, Effect of transparent film desiccant on the lifetime of top-emitting active matrix organic light emitting diodes, Appl. Phys. Lett. (2007) 90,103518.
[35]C. J. Lee, R. B. Pode, J. I. Han, D. G. Moon, Green top-emitting organic light emitting device with transparent Ba/Ag bilayer cathode, Appl. Phys. Lett. (2006) 89,123501.
[36]Q. Huang, K. Walzer, M. Pfeiffer, V. Lyssenko, G. He, K. Leo, Highly efficient top emitting organic light-emitting diodes with organic outcoupling enhancement layers, Appl. Phys. Lett. (2006) 88,113515.
[37]G. L. Ma, G. Z. Ran, A. G. Xu, Y. P. Qiao, W. Q. Zhao, B. R. Zhang, S. K. Wu, G. G. Qin, Novel transparent Yb-based cathodes for top-emitting organic light emitting devices with high performance, Appl. Surf. Sci. (2006) 252,3580.
[38]Burroughes J H, Bradley D D C, Brown A R, et al. Light-emitting diodes based on conjugated polymers[J] Nature 1990,347:539-541.
[39]Braun D, Heeger A J. Visible light emission from semiconducting polymer diodes[J]Appl. phys. Lett.1991,58:1982-1984.
[40]Hung L S, Tang C W, Mason M G, Enhanced electron injection in organic electroluminescence devices using an Al/LiF electrode[J] Appl. phys. Lett.1997 70:152-154.
[41]Baldo M A, O'Brien D F,You Y, et al. Highly efficient phosphorescent emission from organic electroluminescent devices[J].Nature,1998,395:151-154.
[42]Hebner T R, Sturm J C. Local tuning of organic light-emitting diode color by dye droplet application[J].Appl. phys. Lett.1998,73:1775-1777.
[43]Liao L S, Klubek K P, Tang C W. High-efficiency tandem organic light-emitting diodes[J].Appl. phys. Lett.2004,84:167-169.
[44]电子工程专辑http://www.eettaiwan.com/ART_8800359685_617739_41 f77e48_no.HTM
[45]日经BP社http://www.olight.com.cn/Article_Show.asp?ArticleID=2949
[46]Reineke S, Lindner S F, Schwartz G,et al.White organic light-emitting diodes with fluorescent tube efficiency[J]Nature,2009,459:234-238
[47]黄锡珉,平板显示技术的发展[J]液晶与显示,2002,17：317-322
[48]http://tech.163.com/digi/04/0915/09/10AGA3KD001618S7.html
[49]http://www.it.com.cn/f/diy/0710/8/486796.htm
[50]Pichler K, Howard W E,Prache O, Proceedings of the SPIE Conference on Organic Light-Emitting Materials and Devices Ⅲ, Denver, CO,1999,p.258
[51]Feng T,Ali T A,Ramakrishnan E S,et al.Proceedings of the SPIE Conference on Organic Light-Emitting Materials and Devices Ⅳ,2001, p.30.
[52]O. Pache, SID Digest,2001,p.514.
[53]http://www.oled-info.com/lg-3 d-oled-mobile-display-prototype-photo
[54]http://www.oled-info.com/samsung-19-printed-oled-prototype-photo
[55]http://www.oled-info.com/samsung-19-transparent-amoled-photo-0
[56]Y. Yang, E. Westerweele, C. Zhang, P. Smith, A.J. Heeger, J. Appl. Phys.1995,77:694.
[57]L.S. Hung, C.W. Tang, M.G. Mason, Appl. Phys. Lett.1997,70:152.
[58]M.G. Mason, L.S. Hung, C.W. Tang, S.T. Lee, K.W. Wong, M. Wang, J.Appl. Phys. 1999,86:1688.
[59]S.K. Heeks, J.H. Burroughes, C. Towns, S. Cina, N. Baynes, N. Athanassopoulou, J.C. Carter, S. Miyashita, J. Soc. Inf. Disp.2000,10:139.
[60]Qian JC, Jia KP, Yu JS, et al.spectroscopy and spectral analysis(光谱学与光谱分析),2010,30(3)：625.
[61]Guohua Xie, Yanlong Meng, Fengmin Wu, Chen Tao, Dandan Zhang, Mingjun Liu,Qin Xue, Wen Chen, and Yi Zhao, Appl. Phys. Lett.2008,92:093305.
[62]J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett.1998,73:729.
[63]M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett.1998,73:3202.
[64]Y. Luo, H. Aziz, G. Xu, Z.D. Popovic, J. Appl. Phys.2007,101:054512.
[65]Kaushik Roy Choudhury, Jong-hyuk Yoon, and Franky So, Adv. Mater.2008,20:1456.
[66]X.D. Feng, C.J. Huang, V. Lui, R.S. Khangura, Z.H. Lu, Appl. Phys. Lett.2005,86:143511.
[67]S.Y. Chen, T.Y. Chu, J.F. Chen, C.Y. Su, C.H. Chen, Appl. Phys. Lett.2006,89:053518.
[68]J. Huang, G. Li, E. Wu, Q. Xu, Y. Yang, Adv. Mater.2006,18:114.
[69]J. Li, M. Yahiro, K. Ishida, H. Yamadab, K. Matsushige, Synth. Met.2005,151:141.
[70]S.A. Van Slyke, C.H. Chen, C.W. Tang, Appl. Phys. Lett.1996,69:2160.
[71]Xue-Yin Jiang, Zhi-Lin Zhang, Jin Cao, Wen-Qing Zhu, Solid-State Electronics 2008,52:952.
[72]Han You, Yanfeng Dai, Zhiqiang Zhang, and Dongge Ma, J. Appl. Phys. 2007,101:026105.
[73]H. Ikeda, J. Sakata, M. Hayakawa, T. Aoyama, T. Kawakami, K. Kamata, Y. Iwaki,S. Seo, Y. Noda, R. Nomura, S. Yamazaki, SID Digest 2006,37:923.
[74]T. Matsushima, Y. Kinoshita, H. Murata, Appl. Phys. Lett.2007,91:253504.
[75]Hui Wang, Kevin P. Klubek, and C. W. Tang, Appl. Phys.
[76]A.B. Djurisic, A.D. Rakic, Organic microcavity light-emitting diodes with metal mirrors: Dependence of the emission wavelength on the viewing angle, Appl. Opt. (2002)41, 7650.
[77]D.G. Deppe, C. Lei, C.C. Lin, and D.L. Huffaker, spontaneous emission from planar microstructures, (1993)41,325.
[78]黄春辉,李富友,黄岩谊,光电功能超薄膜,北京大学出版社,2001.
[79]W Y Ji, L T Zhang, T Y Zhang, G Q Liu, W F Xie, S Y Liu, H Z Zhang, L Y Zhang, and B Li, Opt. Lett.34(2009)2703.
[80]B. J. Chen, X. W. Sun, and S. C. Tan 2005 Transparent organic light-emitting devices with LiF/Mg:Ag cathode Opt. Express.13937.
[81]G. Gu, V. Bulovic, P. E. Burrows, S. R. Forrest and M. E. Thompson 1996 Transparent organic light emitting devices Appl. Phys. Lett.68 2606.
[82]A. Yamamori, S. Hayashi, T. Koyama and Y. Taniguchi 2001 Transparent organic light-emitting diodes using metal acethylacetonate complexes as an electron injective buffer layer Appl. Phys. Lett.78 3343.
[83]G. Parthasarathy, C. Adachi, P. E. Burrows and S. R. Forrest 2000 High-efficiency transparent organic light-emitting devices Appl. Phys. Lett.76 2128.
[84]G. Parthasarathy, P. E. Burrows, V. Khalfin, V. G. Kozlov and S. R. Forrest 1998 A metal-free cathode for organic semiconductor devices Appl. Phys. Lett.72 2138.
[85]C. J. Lee, R. B. Pode, J. I. Han and D. G. Moon 2007 Ca/Ag bilayer cathode for transparent white organic light-emitting devices Appl. Surf. Sci.253 4249.
[86]汤顺青,色度学,北京理工大学出版社,1990年6月第一版。
[87]J. Lewis, S. Grego, B. Chalamala, E. Vick, and D. Temple, Appl. Phys. Lett.85 (2004) 3450.
[88]J.C.C. Fan, F.J. Bachner, H. Foley, and P.M. Zavracky, Appl. Phys. Lett.25 (1974) 693.
[89]M. Bender, W. Seelig, C. Daube, H. Frankenberger, B. Ocker, and J. Stollenwerk, Thin Solid Films 326 (1998) 67.
[90]K.H. Choi, H.J. Nam, J.A. Jeong, S.W. Cho, H.K. Kim, J.W. Kang, D.G. Kim, and W.J. Cho, Appl. Phys. Lett.92 (2008) 223302.
[91]H.Q. Pang, Y.B. Yuan, Y.F. Zhou, J.R. Lian, L.F. Cao, J.Zhang, and X. Zhou, J. Lumin. 122-123(2007)587.
[92]K.S. Yook, S.O. Jeon, C.W. Joo, and J.Y. Lee, Appl. Phys. Lett.93 (2008) 013301.
[93]S.Y. Ryu, J.H. Noh, B.H. Hwang, C.S. Kim, S.J. Jo, J.T. Kim, H.S. Hwang, H.K. Baik, H.S. Jeong, C.H. Lee, S.Y. Song, S.H. Choi, and S.Y. Park, Appl. Phys. Lett.92 (2008) 023306.
[94]L T Zhang, W F Xie, J Wang, H Z Zhang and Y S Zhang, J. Phys. D:Appl. Phys.39 (2006) 2373-2376.
[2]Helfrich W, Schneider W G.Recombination radiation in anthracene crystals[J]. Phys. Rev. Lett.1965,14:229-231.
[3]Lohmann F, Mehl W.Dark injection and radiative recombination of electrons and holes in naphthalene crystals[J]. J. Chem. Phys.1969,50:500-506.
[4]Williams D M, Schadt M.A simple organic electroluminescence diode[J]. Proc. IEEE, 1970,58:476-476.
[5]Vincett P S, Barlow W A, Hann R A, Roberts G B. Electrical conduction and low voltage blue electroluminescene in vacuum-deposited organic films[J]. Thin Solid Films 1982 94:171-183.
[6]S. A. Vanslyke, C. W. Tang. Organic electroluminescent devices having improved power conversion efficiencies:U. S.4539507 [P] 1985-9-3.
[7]Tang C W, Vanslyke S A.Organic electroluminescent diodes[J]. Appl. Phys. Lett. 1987,51:913-915.
[8]Adachi C, Tolito S, Tsutsui T, Saito S. Organic electroluminescent devices with a Three-layer structure, Jpn. J. Appl. Phys.1988,27:L713-L715.
[9]Adachi C, Tolito S, Tsutsui T, Saito S. Electroluminescence in organic films with a Three-layer structure[J]. Jpn. J. Appl. Phys. (1988) 27:L269-L271.
[10]M.-H. Lu, M. S. Weaver, T. X. Zhou, M. Rothman, R. C. Kwong, M. Hack, J. J. Brown, High-efficiency top-emitting organic light-emitting devices, Appl. Phys. Lett. (2002) 81, 3921.
[11]H. W. Choi, S. Y. Kim, K.-B. Kim, Y. H. Tak, J.-L. Lee, Enhancement of hole injection using O2 plasma-treated Ag anode for top-emitting organic light-emitting diodes, Appl. Phys. Lett. (2005)86,012104.
[12]H. Kanno,Y. Sun, S. R. Forrest, High-efficiency top-emissive white-light-emitting organic electrophosphorescent devices, Appl. Phys. Lett. (2005) 86,263502.
[13]H.-K. Kim, D.-G. Kim, K.-S. Lee, M.-S. Huh, S. H. Jeong, K. I. Kim, H. Kim, D. W. Han, J. H. Kwon, Plasma damage-free deposition of Al cathode on organic light-emitting devices by using mirror shape target sputtering, Appl. Phys. Lett. (2004) 85,4295.
[14]H.-K. Kim, K.-S. Lee, J. H. Kwon, Transparent indium zinc oxide top cathode prepared by plasma damage-free sputtering for top-emitting organic light-emitting diodes, Appl. Phys. Lett. (2006)88,012103.
[15]H. Riel, S. Karg, T. Beierlein, B. Ruhstaller, W. Rieβ, Phosphorescent top-emitting organic light-emitting devices with improved light outcoupling, Appl. Phys. Lett. (2003) 82,466.
[16]S. Han, X. Feng, Z. H. Lu, D. Johnson, R. Wood, Transparent-cathode for top-emission organic light-emitting diodes, Appl. Phys. Lett. (2003) 82,2715.
[17]S. F. Hsu, C.-C. Lee, A. T. Hu, C. H. Chen, Fabrication of blue top-emitting organic light-emitting devices with highly saturated color, Current Applied Physics (2004) 4,663.
[18]C. J. Lee, R. B. Pode, D. G. Moon, J. I. Han, N. H. Park, S. H. Baik, S. S. Ju, On the problem of microcavity effects on the top emitting OLED with semi-transparent metal cathode, Phys. Stat. Sol. (a) (2004) 201,1022.
[19]D. G. Moon, R. B. Pode, C. J. Lee, J. I. Han, Transient electro-phosphorescence in red top-emitting organic light-emitting devices, Appl. Phys. Lett. (2004) 85,4771.
[20]R. B. Pode, C. J. Lee, D. G. Moon, J. I. Han, Transparent conducting metal electrode for top emission organic light-emitting devices:Ca-Ag double layer, Appl. Phys. Lett. (2004) 84,4614.
[21]D.G. Moon, R.B. Pode, C.J. Lee, J.I. Han, Efficient red electro-phosphorescent top-emitting organic light-emitting devices, Materials Science and Engineering B 121 (2005) 232.
[22]S.-F. Hsu, C.-C. Lee, S.-W. Hwang, H.-H. Chen, C. H. Chena, A. T. Hu, Color-saturated and highly efficient top-emitting organic light-emitting devices, Thin Solid Films (2005) 478,271.
[23]Y Li, L.-W. Tan, X.-T. Hao, K. S. Ong, F. Zhu, L.-S. Hung, Flexible top-emitting electroluminescent devices on polyethylene terephthalate substrates, Appl. Phys. Lett. (2005) 86,153508.
[24]S.-F. Hsu, C.-C. Lee, S.-W. Hwang, H.-H. Chen, Highly efficient top-emitting white organic electroluminescent devices, Appl. Phys. Lett. (2005) 86,253508.
[25]B. Xiao, B. Yao, C. Ma, S. Liu, Z. Xie, L. Wang, Highly efficient top-emitting organic light-emitting devices with aluminium electrodes, Semicond. Sci. Technol. (2005) 20, 952.
[26]C.-W. Chen, P.-Y. Hsieh, H.-H. Chiang, C.-L. Lin, H.-M. Wu, C.-C. Wu, Top-emitting organic light-emitting devices using surface-modified Ag anode, Appl. Phys. Lett. (2003) 83,5127.
[27]Y. Q. Li, J.X. Tang, Z.Y. Xie, L.S. Hung, S.S. Lau, An efficient organic light-emitting diode with silver electrodes, Chem. Phys. Lett. (2004) 386,128.
[28]C.-C. Wu, C.-L. Lin, P.-Y. Hsieh, H.-H. Chiang, Methodology for optimizing viewing characteristics of top-emitting organic light-emitting devices, Appl. Phys. Lett. (2004) 84, 3966.
[29]C.-L. Lin, H.-W. Lin, C.-C. Wu, Examining microcavity organic light-emitting devices having two metal mirrors, Appl. Phys. Lett. (2005) 87,021101.
[30]C.-J. Yang, C.-L. Lin, C.-C. Wu, High-contrast top-emitting organic light-emitting devices for active-matrix displays, Appl. Phys. Lett. (2005) 87,143507.
[31]H. Peng, J. Sun, X. Zhu, X. Yu, M. Wong, H.-S. Kwok, High-efficiency microcavity top-emitting organic light-emitting diodes using silver anode, Appl. Phys. Lett. (2006) 88, 073517.
[32]X. Y. Deng, M. K. Ho, and K. Y. Wong, Top-emitting polymer light-emitting diodes with environmentally stable cathodes, J. Appl. Phys. (2006) 99,016103.
[33]J. Y. Lee, Efficient hole injection in organic light-emitting diodes using C60 as a buffer layer for Al reflective anodes, Appl. Phys. Lett. (2006) 88,073512.
[34]B. D. Lee, Y.-H. Cho, W.-J. Kim, M. H. Oh, J. H. Lee, D. S. Zang, Effect of transparent film desiccant on the lifetime of top-emitting active matrix organic light emitting diodes, Appl. Phys. Lett. (2007) 90,103518.
[35]C. J. Lee, R. B. Pode, J. I. Han, D. G. Moon, Green top-emitting organic light emitting device with transparent Ba/Ag bilayer cathode, Appl. Phys. Lett. (2006) 89,123501.
[36]Q. Huang, K. Walzer, M. Pfeiffer, V. Lyssenko, G. He, K. Leo, Highly efficient top emitting organic light-emitting diodes with organic outcoupling enhancement layers, Appl. Phys. Lett. (2006) 88,113515.
[37]G. L. Ma, G. Z. Ran, A. G. Xu, Y. P. Qiao, W. Q. Zhao, B. R. Zhang, S. K. Wu, G. G. Qin, Novel transparent Yb-based cathodes for top-emitting organic light emitting devices with high performance, Appl. Surf. Sci. (2006) 252,3580.
[38]Burroughes J H, Bradley D D C, Brown A R, et al. Light-emitting diodes based on conjugated polymers[J] Nature 1990,347:539-541.
[39]Braun D, Heeger A J. Visible light emission from semiconducting polymer diodes[J]Appl. phys. Lett.1991,58:1982-1984.
[40]Hung L S, Tang C W, Mason M G, Enhanced electron injection in organic electroluminescence devices using an Al/LiF electrode[J] Appl. phys. Lett.1997 70:152-154.
[41]Baldo M A, O'Brien D F,You Y, et al. Highly efficient phosphorescent emission from organic electroluminescent devices[J].Nature,1998,395:151-154.
[42]Hebner T R, Sturm J C. Local tuning of organic light-emitting diode color by dye droplet application[J].Appl. phys. Lett.1998,73:1775-1777.
[43]Liao L S, Klubek K P, Tang C W. High-efficiency tandem organic light-emitting diodes[J].Appl. phys. Lett.2004,84:167-169.
[44]电子工程专辑http://www.eettaiwan.com/ART_8800359685_617739_41 f77e48_no.HTM
[45]日经BP社http://www.olight.com.cn/Article_Show.asp?ArticleID=2949
[46]Reineke S, Lindner S F, Schwartz G,et al.White organic light-emitting diodes with fluorescent tube efficiency[J]Nature,2009,459:234-238
[47]黄锡珉,平板显示技术的发展[J]液晶与显示,2002,17：317-322
[48]http://tech.163.com/digi/04/0915/09/10AGA3KD001618S7.html
[49]http://www.it.com.cn/f/diy/0710/8/486796.htm
[50]Pichler K, Howard W E,Prache O, Proceedings of the SPIE Conference on Organic Light-Emitting Materials and Devices Ⅲ, Denver, CO,1999,p.258
[51]Feng T,Ali T A,Ramakrishnan E S,et al.Proceedings of the SPIE Conference on Organic Light-Emitting Materials and Devices Ⅳ,2001, p.30.
[52]O. Pache, SID Digest,2001,p.514.
[53]http://www.oled-info.com/lg-3 d-oled-mobile-display-prototype-photo
[54]http://www.oled-info.com/samsung-19-printed-oled-prototype-photo
[55]http://www.oled-info.com/samsung-19-transparent-amoled-photo-0
[56]Y. Yang, E. Westerweele, C. Zhang, P. Smith, A.J. Heeger, J. Appl. Phys.1995,77:694.
[57]L.S. Hung, C.W. Tang, M.G. Mason, Appl. Phys. Lett.1997,70:152.
[58]M.G. Mason, L.S. Hung, C.W. Tang, S.T. Lee, K.W. Wong, M. Wang, J.Appl. Phys. 1999,86:1688.
[59]S.K. Heeks, J.H. Burroughes, C. Towns, S. Cina, N. Baynes, N. Athanassopoulou, J.C. Carter, S. Miyashita, J. Soc. Inf. Disp.2000,10:139.
[60]Qian JC, Jia KP, Yu JS, et al.spectroscopy and spectral analysis(光谱学与光谱分析),2010,30(3)：625.
[61]Guohua Xie, Yanlong Meng, Fengmin Wu, Chen Tao, Dandan Zhang, Mingjun Liu,Qin Xue, Wen Chen, and Yi Zhao, Appl. Phys. Lett.2008,92:093305.
[62]J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett.1998,73:729.
[63]M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett.1998,73:3202.
[64]Y. Luo, H. Aziz, G. Xu, Z.D. Popovic, J. Appl. Phys.2007,101:054512.
[65]Kaushik Roy Choudhury, Jong-hyuk Yoon, and Franky So, Adv. Mater.2008,20:1456.
[66]X.D. Feng, C.J. Huang, V. Lui, R.S. Khangura, Z.H. Lu, Appl. Phys. Lett.2005,86:143511.
[67]S.Y. Chen, T.Y. Chu, J.F. Chen, C.Y. Su, C.H. Chen, Appl. Phys. Lett.2006,89:053518.
[68]J. Huang, G. Li, E. Wu, Q. Xu, Y. Yang, Adv. Mater.2006,18:114.
[69]J. Li, M. Yahiro, K. Ishida, H. Yamadab, K. Matsushige, Synth. Met.2005,151:141.
[70]S.A. Van Slyke, C.H. Chen, C.W. Tang, Appl. Phys. Lett.1996,69:2160.
[71]Xue-Yin Jiang, Zhi-Lin Zhang, Jin Cao, Wen-Qing Zhu, Solid-State Electronics 2008,52:952.
[72]Han You, Yanfeng Dai, Zhiqiang Zhang, and Dongge Ma, J. Appl. Phys. 2007,101:026105.
[73]H. Ikeda, J. Sakata, M. Hayakawa, T. Aoyama, T. Kawakami, K. Kamata, Y. Iwaki,S. Seo, Y. Noda, R. Nomura, S. Yamazaki, SID Digest 2006,37:923.
[74]T. Matsushima, Y. Kinoshita, H. Murata, Appl. Phys. Lett.2007,91:253504.
[75]Hui Wang, Kevin P. Klubek, and C. W. Tang, Appl. Phys.
[76]A.B. Djurisic, A.D. Rakic, Organic microcavity light-emitting diodes with metal mirrors: Dependence of the emission wavelength on the viewing angle, Appl. Opt. (2002)41, 7650.
[77]D.G. Deppe, C. Lei, C.C. Lin, and D.L. Huffaker, spontaneous emission from planar microstructures, (1993)41,325.
[78]黄春辉,李富友,黄岩谊,光电功能超薄膜,北京大学出版社,2001.
[79]W Y Ji, L T Zhang, T Y Zhang, G Q Liu, W F Xie, S Y Liu, H Z Zhang, L Y Zhang, and B Li, Opt. Lett.34(2009)2703.
[80]B. J. Chen, X. W. Sun, and S. C. Tan 2005 Transparent organic light-emitting devices with LiF/Mg:Ag cathode Opt. Express.13937.
[81]G. Gu, V. Bulovic, P. E. Burrows, S. R. Forrest and M. E. Thompson 1996 Transparent organic light emitting devices Appl. Phys. Lett.68 2606.
[82]A. Yamamori, S. Hayashi, T. Koyama and Y. Taniguchi 2001 Transparent organic light-emitting diodes using metal acethylacetonate complexes as an electron injective buffer layer Appl. Phys. Lett.78 3343.
[83]G. Parthasarathy, C. Adachi, P. E. Burrows and S. R. Forrest 2000 High-efficiency transparent organic light-emitting devices Appl. Phys. Lett.76 2128.
[84]G. Parthasarathy, P. E. Burrows, V. Khalfin, V. G. Kozlov and S. R. Forrest 1998 A metal-free cathode for organic semiconductor devices Appl. Phys. Lett.72 2138.
[85]C. J. Lee, R. B. Pode, J. I. Han and D. G. Moon 2007 Ca/Ag bilayer cathode for transparent white organic light-emitting devices Appl. Surf. Sci.253 4249.
[86]汤顺青,色度学,北京理工大学出版社,1990年6月第一版。
[87]J. Lewis, S. Grego, B. Chalamala, E. Vick, and D. Temple, Appl. Phys. Lett.85 (2004) 3450.
[88]J.C.C. Fan, F.J. Bachner, H. Foley, and P.M. Zavracky, Appl. Phys. Lett.25 (1974) 693.
[89]M. Bender, W. Seelig, C. Daube, H. Frankenberger, B. Ocker, and J. Stollenwerk, Thin Solid Films 326 (1998) 67.
[90]K.H. Choi, H.J. Nam, J.A. Jeong, S.W. Cho, H.K. Kim, J.W. Kang, D.G. Kim, and W.J. Cho, Appl. Phys. Lett.92 (2008) 223302.
[91]H.Q. Pang, Y.B. Yuan, Y.F. Zhou, J.R. Lian, L.F. Cao, J.Zhang, and X. Zhou, J. Lumin. 122-123(2007)587.
[92]K.S. Yook, S.O. Jeon, C.W. Joo, and J.Y. Lee, Appl. Phys. Lett.93 (2008) 013301.
[93]S.Y. Ryu, J.H. Noh, B.H. Hwang, C.S. Kim, S.J. Jo, J.T. Kim, H.S. Hwang, H.K. Baik, H.S. Jeong, C.H. Lee, S.Y. Song, S.H. Choi, and S.Y. Park, Appl. Phys. Lett.92 (2008) 023306.
[94]L T Zhang, W F Xie, J Wang, H Z Zhang and Y S Zhang, J. Phys. D:Appl. Phys.39 (2006) 2373-2376.