SEMICONDUCTOR DEVICES

Numerical model of tandem organic light-emitting diodes based on a transition metal oxide interconnector layer

Feiping Lu1, , Yingquan Peng2 and Yongzhong Xing1

+ Author Affiliations

 Corresponding author: Lu Feiping, Email: lufp_sysu@163.com

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Abstract: By utilizing a two-step process to express the charge generation and separation mechanism of the transition metal oxides (TMOs) interconnector layer, a numerical model was proposed for tandem organic light emitting diodes (OLEDs) with a TMOs thin film as the interconnector layer. This model is valid not only for an n-type TMOs interconnector layer, but also for a p-type TMOs interconnector layer. Based on this model, the influences of different carrier injection barriers at the interface of the electrode/organic layer on the charge generation ability of interconnector layers were studied. In addition, the distribution characteristics of carrier concentration, electric field intensity and potential in the device under different carrier injection barriers were studied. The results show that when keeping one carrier injection barrier as a constant while increasing another carrier injection barrier, carriers injected into the device were gradually decreased, the carrier generation ability of the interconnector layer was gradually reduced, the electric field intensity at the interface of the organic/electrode was gradually enhanced, and the electric field distribution became nearly linear:the voltage drops in two light units gradually became the same. Meanwhile, the carrier injection ability decreased as another carrier injection barrier increased. The simulation results agree with the experimental data. The obtained results can provide us with a deep understanding of the work mechanism of TMOs-based tandem OLEDs.

Key words: tandem organic light-emitting diodesnumerical modelinterconnector layertransition metal oxide



[1]
Reineke S, Lindner F, Schwartz G, et al. White organic light-emitting diodes with fluorescent tube efficiency. Nature, 2009, 459(7244):234 doi: 10.1038/nature08003
[2]
Zhang Yongwen, Chen Wenbin, Liu Haohan. A new AC driving circuit for a top emission AMOLED. Journal of Semiconductors, 2013, 34(5):055005 doi: 10.1088/1674-4926/34/5/055005
[3]
Wang Huan, Wang Zhigong, Feng Jun, et al. A pixel circuit with reduced switching leakage for an organic light-emitting diode. Journal of Semiconductors, 2012, 33(12):125006 doi: 10.1088/1674-4926/33/12/125006
[4]
Zhao Bohua, Huang Ran, Bu Jianhui, et al. A new OLED SPICE model for pixel circuit simulation in OLED-on-silicon microdisplay design. Journal of Semiconductors, 2012, 33(7):075007 doi: 10.1088/1674-4926/33/7/075007
[5]
Zhao Bohua, Huang Ran, Ma Fei, et al. The realization of an SVGA OLED-on-silicon microdisplay driving circuit. Journal of Semiconductors, 2012, 33(3):035006 doi: 10.1088/1674-4926/33/3/035006
[6]
Huang Ran, Wang Xiaohui, Wang Wenbo, et al. Design of a 16 gray scales 32040 pixels OLED-on-silicon driving circuit. Journal of Semiconductors, 2009, 30(1):015010 doi: 10.1088/1674-4926/30/1/015010
[7]
Chiba T, Pu Y J, Miyazaki R, et al. Ultra-high efficiency by multiple emission from stacked organic light-emitting devices. Org Electron, 2011, 12(4):710 doi: 10.1016/j.orgel.2011.01.022
[8]
Liao L S, Slusarek W K, Hatwar T K, et al. Tandem organic light-emitting diode using hexaazatriphenylene hexacarbonitrile in the intermediate connector. Adv Mater, 2008, 20(2):324 doi: 10.1002/(ISSN)1521-4095
[9]
Chen C W, Lu Y J, Wu C C, et al. Effective connecting architecture for tandem organic light-emitting devices. Appl Phys Lett, 2005, 87(24):241121 doi: 10.1063/1.2141718
[10]
Tsutsui T, Terai M. Electric field-assisted bipolar charge spouting in organic thin-film diodes. Appl Phys Lett, 2004, 84(3):440 doi: 10.1063/1.1640470
[11]
Kanno H, Holmes R J, Sun Y, et al. White stacked electrophosphorescent organic light-emitting devices employing MoO3 as a charge-generation layer. Adv Mater, 2006, 18(3):339 doi: 10.1002/(ISSN)1521-4095
[12]
Chen P, Xue Q, Xie W, et al. Influence of interlayer on the performance of stacked white organic light-emitting devices. Appl Phys Lett, 2009, 95(12):123307 doi: 10.1063/1.3234379
[13]
Guo F, Ma D. White organic light-emitting diodes based on tandem structures. Appl Phys Lett, 2005, 87(17):173510 doi: 10.1063/1.2120898
[14]
Liao L S, Klubek K P, Tang C W. High-efficiency tandem organic light-emitting diodes. Appl Phys Lett, 2004, 84(2):167 doi: 10.1063/1.1638624
[15]
Meyer J, Kröger M, Hamwi S, et al. Charge generation layers comprising transition metal-oxide/organic interfaces:electronic structure and charge generation mechanism. Appl Phys Lett, 2010, 96:193302 doi: 10.1063/1.3427430
[16]
Lu F P, Wang Q, Zhou X. Tandem organic light-emitting diode with a molybdenum tri-oxide thin film interconnector layer. Chinese Physics B, 2013, 22(3):037202 doi: 10.1088/1674-1056/22/3/037202
[17]
Chang C C, Hwang S W, Chen C H, et al. High-efficiency organic electroluminescent device with multiple emitting units. Jpn J Appl Phys, 2004, 43:6418 doi: 10.1143/JJAP.43.6418
[18]
Zhang H M, Dai Y F, Ma D G, et al. High efficiency tandem organic light-emitting devices with Al/WO3/Au interconnecting layer. Appl Phys Lett, 2007, 91(12):123504 doi: 10.1063/1.2787877
[19]
Terai M, Fujita K, Tsutsui T. Capacitance measurement in organic thin-film device with internal charge separation zone. Jpn J Appl Phys, 2005, 44:L1059 doi: 10.1143/JJAP.44.L1059
[20]
Qi X, Li N, Forrest S R. Analysis of metal-oxide-based charge generation layers used in stacked organic light-emitting diodes. J Appl Phys, 2010, 107(1):014514 doi: 10.1063/1.3275050
[21]
Cheng Y M, Lu H H, Jen T H, et al. Role of the charge generation layer in tandem organic light-emitting diodes investigated by time-resolved electroluminescence spectroscopy. J Phys Chem C, 2010, 115(2):582 doi: 10.1021/jp1095085
[22]
Bao Q Y, Yang J P, Tang J X, et al. Interfacial electronic structures of WO3-based intermediate connectors in tandem organic light-emitting diodes. Org Electron, 2010, 11(9):1578 doi: 10.1016/j.orgel.2010.07.009
[23]
Bao Q Y, Yang J P, Li Y Q, et al. Electronic structures of MoO3-based charge generation layer for tandem organic light-emitting diode. Appl Phys Lett, 2010, 97:063303 doi: 10.1063/1.3479477
[24]
Kihyon H, Lee J L. Charge generation mechanism of metal oxide interconnection in tandem organic light emitting diodes. J Phys Chem C, 2012, 116(10):6427 doi: 10.1021/jp212090b
[25]
Yang J P, Xiao Y, Deng Y H, et al. Electric-field-assisted charge generation and separation process in transition metal oxide-based interconnectors for tandem organic light-emitting diodes. Adv Funct Mater, 2012, 22(3):600 doi: 10.1002/adfm.201102136
[26]
Jens M, Sami H, Michael K, et al. Transition metal oxides for organic electronics:energetics, device physics and applications. Adv Mater, 2012, 24(40):5408 doi: 10.1002/adma.v24.40
[27]
Kaname K, Kenji K, Satoru O, et al. Electronic structure of anode interface with molybdenum oxide buffer layer. Org Electron, 2009, 10:637 doi: 10.1016/j.orgel.2009.02.017
[28]
Min J S, Sehun K, Soonnam K, et al. Interface electronic structures of organic light-emitting diodes with WO3 interlayer:a study by photoelectron spectroscopy. Org Electron, 2009, 10(4):637 doi: 10.1016/j.orgel.2009.02.017
[29]
Davids P S, Kogan S M, Parker I D, et al. Charge injection in organic light-emitting diodes:tunneling into low mobility materials. Appl Phys Lett, 1996, 69(15):2270 doi: 10.1063/1.117530
[30]
Davids P S, Campbell I H, Smith D L. Device model for single carrier organic diodes. J Appl Phys, 1997, 82(12):6319 doi: 10.1063/1.366522
[31]
Campbell A J, Bradley D D C, Lidzey D G. Space-charge limited conduction with traps in poly (phenylene vinylene) light emitting diodes. J Appl Phys, 1997, 82(12):6326 doi: 10.1063/1.366523
[32]
Blom P W M, De Jong M J M, Breedijk S. Temperature dependent electron-hole recombination in polymer light-emitting diodes. Appl Phys Lett, 1997, 71(7):930 doi: 10.1063/1.119692
[33]
Peng Y Q, Yang Q S, Xing H W, et al. Recombination zone and efficiency in bipolar single layer light-emitting devices:a numerical study. Appl Phys A, 2008, 93(2):559 doi: 10.1007/s00339-008-4669-x
[34]
Gummel H K. A self-consistent iterative scheme for one-dimensional steady state transistor calculations. IEEE Trans Electron Devices, 1964, 11(10):455 doi: 10.1109/T-ED.1964.15364
[35]
Scharfetter D L, Gummel H K. Large-signal analysis of a silicon read diode oscillator. IEEE Trans Electron Devices, 1969, 16(1):64 doi: 10.1109/T-ED.1969.16566
Fig. 1.  Diagram of charge generation process in n-type TMO-based interconnector layer.

Fig. 2.  The schematic of the injection and leakage current density for holes ($J_{\rm h}$, $ J$ $^{'}_{\rm h})$ and electrons ($J_{\rm e}$, $J$ $^{'}_{\rm e})$ of both light emitting units.

Fig. 3.  The electron distribution in tandem OLED with different electron injection barriers.

Fig. 4.  The hole distribution in tandem OLED with different electron injection barriers.

Fig. 5.  The electric field distribution in tandem OLED with different electron injection barriers.

Fig. 6.  The carrier concentration and electric field distribution in tandem OLED with the injection barrier $\phi_{\rm e}$ $=$ 0.3 eV and $\phi_{\rm h}$ $=$ 0.5 eV.

Fig. 7.  The carrier concentration and electric field distribution in tandem OLED with the injection barrier $\phi_{\rm e}$ $=$ 0.7 eV and $\phi _{\rm h}$ $=$ 0.5 eV.

Fig. 8.  The potential distribution in tandem OLED with different electron injection barriers.

Fig. 9.  The hole distribution in tandem OLED with different hole injection barriers.

Fig. 10.  The electron distribution in tandem OLED with different hole injection barriers.

Fig. 11.  The electric field distribution in tandem OLED with different hole injection barriers.

Fig. 12.  The carrier concentration and electric field distribution in tandem OLED with the injection barrier $\phi_{\rm e}$ $=$ 0.5 eV and $\phi _{\rm h}$ $=$ 0.3 eV.

Fig. 13.  The carrier concentration and electric field distribution in tandem OLED with the injection barrier $\phi_{\rm e}$ $=$ 0.5 eV and $\phi _{\rm h}$ $=$ 0.7 eV.

Fig. 14.  The potential distribution in tandem OLED with different hole injection barriers.

Fig. 15.  $J$--$V$ characteristics of devices A and B.

Fig. 16.  A comparison of simulation results with experimental results.

Table 1.   The parameters used in the simulation.

[1]
Reineke S, Lindner F, Schwartz G, et al. White organic light-emitting diodes with fluorescent tube efficiency. Nature, 2009, 459(7244):234 doi: 10.1038/nature08003
[2]
Zhang Yongwen, Chen Wenbin, Liu Haohan. A new AC driving circuit for a top emission AMOLED. Journal of Semiconductors, 2013, 34(5):055005 doi: 10.1088/1674-4926/34/5/055005
[3]
Wang Huan, Wang Zhigong, Feng Jun, et al. A pixel circuit with reduced switching leakage for an organic light-emitting diode. Journal of Semiconductors, 2012, 33(12):125006 doi: 10.1088/1674-4926/33/12/125006
[4]
Zhao Bohua, Huang Ran, Bu Jianhui, et al. A new OLED SPICE model for pixel circuit simulation in OLED-on-silicon microdisplay design. Journal of Semiconductors, 2012, 33(7):075007 doi: 10.1088/1674-4926/33/7/075007
[5]
Zhao Bohua, Huang Ran, Ma Fei, et al. The realization of an SVGA OLED-on-silicon microdisplay driving circuit. Journal of Semiconductors, 2012, 33(3):035006 doi: 10.1088/1674-4926/33/3/035006
[6]
Huang Ran, Wang Xiaohui, Wang Wenbo, et al. Design of a 16 gray scales 32040 pixels OLED-on-silicon driving circuit. Journal of Semiconductors, 2009, 30(1):015010 doi: 10.1088/1674-4926/30/1/015010
[7]
Chiba T, Pu Y J, Miyazaki R, et al. Ultra-high efficiency by multiple emission from stacked organic light-emitting devices. Org Electron, 2011, 12(4):710 doi: 10.1016/j.orgel.2011.01.022
[8]
Liao L S, Slusarek W K, Hatwar T K, et al. Tandem organic light-emitting diode using hexaazatriphenylene hexacarbonitrile in the intermediate connector. Adv Mater, 2008, 20(2):324 doi: 10.1002/(ISSN)1521-4095
[9]
Chen C W, Lu Y J, Wu C C, et al. Effective connecting architecture for tandem organic light-emitting devices. Appl Phys Lett, 2005, 87(24):241121 doi: 10.1063/1.2141718
[10]
Tsutsui T, Terai M. Electric field-assisted bipolar charge spouting in organic thin-film diodes. Appl Phys Lett, 2004, 84(3):440 doi: 10.1063/1.1640470
[11]
Kanno H, Holmes R J, Sun Y, et al. White stacked electrophosphorescent organic light-emitting devices employing MoO3 as a charge-generation layer. Adv Mater, 2006, 18(3):339 doi: 10.1002/(ISSN)1521-4095
[12]
Chen P, Xue Q, Xie W, et al. Influence of interlayer on the performance of stacked white organic light-emitting devices. Appl Phys Lett, 2009, 95(12):123307 doi: 10.1063/1.3234379
[13]
Guo F, Ma D. White organic light-emitting diodes based on tandem structures. Appl Phys Lett, 2005, 87(17):173510 doi: 10.1063/1.2120898
[14]
Liao L S, Klubek K P, Tang C W. High-efficiency tandem organic light-emitting diodes. Appl Phys Lett, 2004, 84(2):167 doi: 10.1063/1.1638624
[15]
Meyer J, Kröger M, Hamwi S, et al. Charge generation layers comprising transition metal-oxide/organic interfaces:electronic structure and charge generation mechanism. Appl Phys Lett, 2010, 96:193302 doi: 10.1063/1.3427430
[16]
Lu F P, Wang Q, Zhou X. Tandem organic light-emitting diode with a molybdenum tri-oxide thin film interconnector layer. Chinese Physics B, 2013, 22(3):037202 doi: 10.1088/1674-1056/22/3/037202
[17]
Chang C C, Hwang S W, Chen C H, et al. High-efficiency organic electroluminescent device with multiple emitting units. Jpn J Appl Phys, 2004, 43:6418 doi: 10.1143/JJAP.43.6418
[18]
Zhang H M, Dai Y F, Ma D G, et al. High efficiency tandem organic light-emitting devices with Al/WO3/Au interconnecting layer. Appl Phys Lett, 2007, 91(12):123504 doi: 10.1063/1.2787877
[19]
Terai M, Fujita K, Tsutsui T. Capacitance measurement in organic thin-film device with internal charge separation zone. Jpn J Appl Phys, 2005, 44:L1059 doi: 10.1143/JJAP.44.L1059
[20]
Qi X, Li N, Forrest S R. Analysis of metal-oxide-based charge generation layers used in stacked organic light-emitting diodes. J Appl Phys, 2010, 107(1):014514 doi: 10.1063/1.3275050
[21]
Cheng Y M, Lu H H, Jen T H, et al. Role of the charge generation layer in tandem organic light-emitting diodes investigated by time-resolved electroluminescence spectroscopy. J Phys Chem C, 2010, 115(2):582 doi: 10.1021/jp1095085
[22]
Bao Q Y, Yang J P, Tang J X, et al. Interfacial electronic structures of WO3-based intermediate connectors in tandem organic light-emitting diodes. Org Electron, 2010, 11(9):1578 doi: 10.1016/j.orgel.2010.07.009
[23]
Bao Q Y, Yang J P, Li Y Q, et al. Electronic structures of MoO3-based charge generation layer for tandem organic light-emitting diode. Appl Phys Lett, 2010, 97:063303 doi: 10.1063/1.3479477
[24]
Kihyon H, Lee J L. Charge generation mechanism of metal oxide interconnection in tandem organic light emitting diodes. J Phys Chem C, 2012, 116(10):6427 doi: 10.1021/jp212090b
[25]
Yang J P, Xiao Y, Deng Y H, et al. Electric-field-assisted charge generation and separation process in transition metal oxide-based interconnectors for tandem organic light-emitting diodes. Adv Funct Mater, 2012, 22(3):600 doi: 10.1002/adfm.201102136
[26]
Jens M, Sami H, Michael K, et al. Transition metal oxides for organic electronics:energetics, device physics and applications. Adv Mater, 2012, 24(40):5408 doi: 10.1002/adma.v24.40
[27]
Kaname K, Kenji K, Satoru O, et al. Electronic structure of anode interface with molybdenum oxide buffer layer. Org Electron, 2009, 10:637 doi: 10.1016/j.orgel.2009.02.017
[28]
Min J S, Sehun K, Soonnam K, et al. Interface electronic structures of organic light-emitting diodes with WO3 interlayer:a study by photoelectron spectroscopy. Org Electron, 2009, 10(4):637 doi: 10.1016/j.orgel.2009.02.017
[29]
Davids P S, Kogan S M, Parker I D, et al. Charge injection in organic light-emitting diodes:tunneling into low mobility materials. Appl Phys Lett, 1996, 69(15):2270 doi: 10.1063/1.117530
[30]
Davids P S, Campbell I H, Smith D L. Device model for single carrier organic diodes. J Appl Phys, 1997, 82(12):6319 doi: 10.1063/1.366522
[31]
Campbell A J, Bradley D D C, Lidzey D G. Space-charge limited conduction with traps in poly (phenylene vinylene) light emitting diodes. J Appl Phys, 1997, 82(12):6326 doi: 10.1063/1.366523
[32]
Blom P W M, De Jong M J M, Breedijk S. Temperature dependent electron-hole recombination in polymer light-emitting diodes. Appl Phys Lett, 1997, 71(7):930 doi: 10.1063/1.119692
[33]
Peng Y Q, Yang Q S, Xing H W, et al. Recombination zone and efficiency in bipolar single layer light-emitting devices:a numerical study. Appl Phys A, 2008, 93(2):559 doi: 10.1007/s00339-008-4669-x
[34]
Gummel H K. A self-consistent iterative scheme for one-dimensional steady state transistor calculations. IEEE Trans Electron Devices, 1964, 11(10):455 doi: 10.1109/T-ED.1964.15364
[35]
Scharfetter D L, Gummel H K. Large-signal analysis of a silicon read diode oscillator. IEEE Trans Electron Devices, 1969, 16(1):64 doi: 10.1109/T-ED.1969.16566
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    Received: 18 November 2013 Revised: 13 February 2014 Online: Published: 01 April 2014

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      Feiping Lu, Yingquan Peng, Yongzhong Xing. Numerical model of tandem organic light-emitting diodes based on a transition metal oxide interconnector layer[J]. Journal of Semiconductors, 2014, 35(4): 044005. doi: 10.1088/1674-4926/35/4/044005 F P Lu, Y Q Peng, Y Z Xing. Numerical model of tandem organic light-emitting diodes based on a transition metal oxide interconnector layer[J]. J. Semicond., 2014, 35(4): 044005. doi: 10.1088/1674-4926/35/4/044005.Export: BibTex EndNote
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      Feiping Lu, Yingquan Peng, Yongzhong Xing. Numerical model of tandem organic light-emitting diodes based on a transition metal oxide interconnector layer[J]. Journal of Semiconductors, 2014, 35(4): 044005. doi: 10.1088/1674-4926/35/4/044005

      F P Lu, Y Q Peng, Y Z Xing. Numerical model of tandem organic light-emitting diodes based on a transition metal oxide interconnector layer[J]. J. Semicond., 2014, 35(4): 044005. doi: 10.1088/1674-4926/35/4/044005.
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      Numerical model of tandem organic light-emitting diodes based on a transition metal oxide interconnector layer

      doi: 10.1088/1674-4926/35/4/044005
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      Project supported by the National Natural Science Foundation of China (Nos. 11265013, 11264033), the Research Fund for the Doctoral Program of Higher Education of China (No. 20110211110005), and the Science Research Foundation of Tianshui Normal University (No. TSA1108)

      the National Natural Science Foundation of China 11264033

      the National Natural Science Foundation of China 11265013

      the Science Research Foundation of Tianshui Normal University TSA1108

      the Research Fund for the Doctoral Program of Higher Education of China 20110211110005

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      • Corresponding author: Lu Feiping, Email: lufp_sysu@163.com
      • Received Date: 2013-11-18
      • Revised Date: 2014-02-13
      • Published Date: 2014-04-01

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