We report a feasible method to realize tunable surface plasmon-polariton (SPP) resonance in organic light-emitting devices (OLEDs) by employing corrugated Ag-Al alloy electrodes. The excited SPP resonance induced by the periodic corrugations can be precisely tuned based on the composition ratios of the Ag-Al alloy electrodes. With an appropriate composition ratio of the corrugated alloy electrode, the photons trapped in SPP modes are recovered and extracted effectively. The 25% increasement in luminance and 21% enhancement in current efficiency have been achieved by using the corrugated Ag-Al alloy electrodes in OLEDs.
|||Liu LH, Li SL, Wu L, Chen DF, Cao K et al. Enhanced flexibility and stability of PEDOT:PSS electrodes through interfacial crosslinking for flexible organic light-emitting diodes. Org Electron 89, 106047 (2021). doi: 10.1016/j.orgel.2020.106047|
|||Jeon Y, Choi HR, Kwon JH, Choi S, Nam KM et al. Sandwich-structure transferable free-form OLEDs for wearable and disposable skin wound photomedicine. Light Sci Appl 8, 114 (2019). doi: 10.1038/s41377-019-0221-3|
|||Yin D, Chen ZY, Jiang NR, Liu YF, Bi YG et al. Highly transparent and flexible fabric-based organic light emitting devices for unnoticeable wearable displays. Org Electron 76, 105494 (2020). doi: 10.1016/j.orgel.2019.105494|
|||Ding R, Dong FX, An MH, Wang XP, Wang MR et al. High-color-rendering and high-efficiency white organic light-emitting devices based on double-doped organic single crystals. Adv Funct Mater 29, 1807606 (2019). doi: 10.1002/adfm.201807606|
|||Huang YG, Hsiang EL, Deng MY, Wu ST. Mini-LED, Micro-LED and OLED displays: present status and future perspectives. Light Sci Appl 9, 105 (2020). doi: 10.1038/s41377-020-0341-9|
|||Song MG, Kim KS, Yang HI, Kim SK, Kim JH et al. Highly reliable and transparent Al doped Ag cathode fabricated using thermal evaporation for transparent OLED applications. Org Electron 76, 105418 (2020). doi: 10.1016/j.orgel.2019.105418|
|||Yin D, Jiang NR, Liu YF, Zhang XL, Li AW et al. Mechanically robust stretchable organic optoelectronic devices built using a simple and universal stencil-pattern transferring technology. Light Sci Appl 7, 35 (2018). doi: 10.1038/s41377-018-0041-x|
|||Baek K, Lee DM, Lee YJ, Choi H, Seo J et al. Simultaneous emission of orthogonal handedness in circular polarization from a single luminophore. Light Sci Appl 8, 120 (2019). doi: 10.1038/s41377-019-0232-0|
|||Feng J, Liu YF, Bi YG, Sun HB. Light manipulation in organic light-emitting devices by integrating micro/nano patterns. Laser Photonics Rev 11, 1600145 (2017). doi: 10.1002/lpor.201600145|
|||Qu Y, Kim J, Coburn C, Forrest SR. Efficient, nonintrusive outcoupling in organic light emitting devices using embedded microlens arrays. ACS Photonics 5, 2453–2458 (2018). doi: 10.1021/acsphotonics.8b00255|
|||Salehi A, Fu XY, Shin DH, So F. Recent advances in OLED optical design. Adv Funct Mater 29, 1808803 (2019). doi: 10.1002/adfm.201808803|
|||Zhou L, Ou QD, Li YQ, Xiang HY, Xu LH et al. Efficiently releasing the trapped energy flow in white organic light-emitting diodes with multifunctional nanofunnel arrays. Adv Funct Mater 25, 2660–2668 (2015). doi: 10.1002/adfm.201500310|
|||Choi J, Shim YS, Park CH, Hwang H, Kwack JH et al. Junction-free electrospun ag fiber electrodes for flexible organic light-emitting diodes. Small 14, 1702567 (2018). doi: 10.1002/smll.201702567|
|||Putnin T, Lertvachirapaiboon C, Ishikawa R, Shinbo K, Kato K et al. Enhanced organic solar cell performance: Multiple surface plasmon resonance and incorporation of silver nanodisks into a grating-structure electrode. Opto-Electron Adv 2, 190010 (2019). doi: 10.29026/oea.2019.190010|
|||Bi YG, Liu YF, Zhang XL, Yin D, Wang WQ et al. Ultrathin metal films as the transparent electrode in ITO-free organic optoelectronic devices. Adv Opt Mater 7, 1800778 (2019). doi: 10.1002/adom.201800778|
|||Morales-Masis M, De Wolf S, Woods-Robinson R, Ager JW, Ballif C. Transparent electrodes for efficient optoelectronics. Adv Electron Mater 3, 1600529 (2017). doi: 10.1002/aelm.201600529|
|||Ho MD, Liu YY, Dong DS, Zhao YM, Cheng WL. Fractal gold nanoframework for highly stretchable transparent strain-insensitive conductors. Nano Lett 18, 3593–3599 (2018). doi: 10.1021/acs.nanolett.8b00694|
|||Yi FS, Bi YG, Zhang XL, Yin D, Liu YF et al. Highly flexible and mechanically robust ultrathin Au grid as electrodes for flexible organic light-emitting devices. IEEE Trans Nanotechnol 18, 776–780 (2019). doi: 10.1109/TNANO.2019.2928689|
|||Barnes WL, Dereux A, Ebbesen TW. Surface plasmon subwavelength optics. Nature 424, 824–830 (2003). doi: 10.1038/nature01937|
|||Ma C, Gao XM, Bi YG, Yi FS, Zhang XL et al. Directly imprinted periodic corrugation on ultrathin metallic electrode for enhanced light extraction in organic light-emitting devices. IEEE Trans Nanotechnol 18, 1057–1062 (2019). doi: 10.1109/TNANO.2019.2936035|
|||Bi YG, Feng J, Liu YS, Li YF, Chen Y et al. Surface plasmon-polariton mediated red emission from organic light-emitting devices based on metallic electrodes integrated with dual-periodic corrugation. Sci Rep 4, 7108 (2014).|
|||Xu M, Feng J, Liu YS, Jin Y, Wang HY et al. Effective and tunable light trapping in bulk heterojunction organic solar cells by employing Au-Ag alloy nanoparticles. Appl Phys Lett 105, 153303 (2014). doi: 10.1063/1.4898137|
|||Huang CY, Zhang XP, Wang JS, Hong CY. Toward electrically pumped polymer lasing: light-emitting diodes based on microcavity arrays of distributed bragg gratings. Adv Opt Mater 6, 1800806 (2018). doi: 10.1002/adom.201800806|
|||Liang HW, Hsu HC, Wu JN, He XF, Wei MK et al. Corrugated organic light-emitting diodes to effectively extract internal modes. Opt Express 27, A372–A384 (2019). doi: 10.1364/OE.27.00A372|
|||Garcia RF, Zeng L, Khadir S, Chakaroun M, Fischer APA et al. Enhanced electroluminescence of an organic light-emitting diode by localized surface plasmon using Al periodic structure. J Opt Soc Am B 33, 246–252 (2016). doi: 10.1364/JOSAB.33.000246|
|||Lindquist NC, Luhman WA, Oh SH, Holmes RJ. Plasmonic nanocavity arrays for enhanced efficiency in organic photovoltaic cells. Appl Phys Lett 93, 123308 (2008). doi: 10.1063/1.2988287|
|||Deng LL, Yang JQ, Zhan N, Yu TY, Yu HT et al. High-performance solution-processed white organic light-emitting diodes based on silica-coated silver nanocubes. Opt Lett 44, 983–986 (2019). doi: 10.1364/OL.44.000983|
|||Andrew P, Barnes WL. Energy transfer across a metal film mediated by surface plasmon polaritons. Science 306, 1002–1005 (2004). doi: 10.1126/science.1102992|
|||Liu YS, Guo S, Yi FS, Feng J, Sun HB. Highly flexible organic-inorganic hybrid perovskite light-emitting devices based on an ultrathin Au electrode. Opt Lett 43, 5524–5527 (2018). doi: 10.1364/OL.43.005524|
|||Bi YG, Feng J, Li YF, Jin Y, Liu YF et al. Enhanced efficiency of organic light-emitting devices with metallic electrodes by integrating periodically corrugated structure. Appl Phys Lett 100, 053304 (2012). doi: 10.1063/1.3680595|
Fabrication process of the periodic corrugations based on NIL. (a) Si template with 290 nm periodic corrugations. (b) PDMS was spin-coated on Si template. (c) Solidified PDMS film was peeled off. (d) The corrugations were transferred to PDMS template. (e) SU-8 was spin-coated on a pre-cleaned glass substrate. (f) Prepared PDMS template was placed on the SU-8 film. (g) NIL processes were applied. (h) The periodic corrugations were prepared on the substrate.
The AFM images of corrugations (a) prepared on glass substrate by NIL and (b) after deposition of ultrathin Au electrode. (c) and (d) are the height profiles of corrugations on the substrate and Au electrode, respectively. The periodic corrugations before and after deposition of Au film show consistent surface morphologies.
(a) Measured and (b) simulated absorption spectra of OLEDs based on Ag, Al, Au, Cu metal cathodes
(a) The normalized absorption spectra of OLEDs based on Ag cathode (black line), Al cathode (green line), Ag0.952Al0.048 alloy cathode (red line), Ag0.909Al0.091 alloy cathode (blue line), and Ag0.870Al0.130 alloy cathode (magenta line), respectively. (b) The angle-dependent absorption spectra of OLEDs based on Ag0.909Al0.091 alloy cathode. The inset in (a) shows the absorption spectra of OLEDs based on various cathodes without normalization.
EL performance of OLEDs based on Ag-Al alloy cathodes with and without corrugations. (a) Current density-voltage and (b) efficiency-current density-luminance features, and (c) normalized EL spectra of corrugated and planar OLEDs. (d) The angle-dependent EL spectra of the corrugated OLEDs under TM polarization. The inset in (a) shows the photos of corrugated OLEDs and planar OLEDs operated at 6 V.