Kinner Lukas, Dimopoulos Theodoros, Ligorio Giovanni, List-Kratochvil Emil J W, Hermerschmidt Felix
Humboldt-Universität zu Berlin, Institut für Physik, Institut für Chemie & IRIS Adlershof Zum Groβen Windkanal 2 12489 Berlin Germany
AIT Austrian Institute of Technology, Center for Energy, Photovoltaic Systems Giefinggasse 6 1210 Vienna Austria
RSC Adv. 2021 May 12;11(28):17324-17331. doi: 10.1039/d1ra02214h. eCollection 2021 May 6.
The broad application of flexible optoelectronic devices is still hampered by the lack of an ITO-free and highly flexible transparent electrode. Dielectric/metal/dielectric (DMD) transparent electrodes are promising candidates to replace ITO, especially in flexible devices due to their mechanical stability to bending, high optical transmittance and low sheet resistance (<6 Ω sq). This paper reports on organic light emitting diodes (OLEDs) employing a DMD electrode, specifically TiO /Ag/Al:ZnO (doped with 2 wt% AlO) fabricated by sputter deposition, together with a solution-processed organic polymeric emitting layer. The electrodes were sputtered without substrate heating on rigid glass and flexible polyethylene terephthalate (PET). The results showed that the OLED devices on the DMD electrodes outperform the OLEDs on commercial ITO substrates in terms of maximum luminance as well as current efficacy. Specifically, DMD-based devices achieve up to 30% higher current efficacy on glass and up to 260% higher efficacy on PET, as compared to the ITO-based reference devices. Maximum luminance reaches up to 100 000 cd m for the DMD-based OLEDs on glass and 43 000 cd m for those on PET. This performance is due to the low sheet resistance of the electrodes combined with efficient light outcoupling and shows the potential of DMDs to replace ITO in optoelectronic devices. This outstanding type of optoelectronic device paves the way for the future high throughput production of flexible display and photovoltaic devices.
缺乏无铟锡氧化物（ITO）且具有高柔韧性的透明电极，仍然阻碍着柔性光电器件的广泛应用。介电/金属/介电（DMD）透明电极有望替代ITO，特别是在柔性器件中，因为它们对弯曲具有机械稳定性、高透光率和低方块电阻（<6Ω/sq）。本文报道了采用DMD电极的有机发光二极管（OLED），具体为通过溅射沉积制备的TiO/Ag/Al:ZnO（掺杂2 wt% AlO），以及溶液处理的有机聚合物发光层。在刚性玻璃和柔性聚对苯二甲酸乙二酯（PET）上溅射电极时不进行衬底加热。结果表明，基于DMD电极的OLED器件在最大亮度和电流效率方面均优于商用ITO衬底上的OLED。具体而言，与基于ITO的参考器件相比，基于DMD的器件在玻璃上的电流效率提高了30%，在PET上提高了260%。基于DMD的OLED在玻璃上的最大亮度达到100000 cd/m²，在PET上达到43000 cd/m²。这种性能归因于电极的低方块电阻以及高效的光输出耦合，显示了DMD在光电器件中替代ITO的潜力。这种出色的光电器件为未来柔性显示器和光伏器件的高通量生产铺平了道路。
