Hyung Gun Woo, Park Jaehoon, Koo Ja-Ryong, Lee Seok Jae, Lee Ho Won, Kim You Hyun, Kim Woo Young, Kim Young Kwan
Department of Materials Science and Engineering, Hongik University, Seoul 121-791, Korea.
J Nanosci Nanotechnol. 2012 Jul;12(7):5444-8. doi: 10.1166/jnn.2012.6232.
In this paper, the improved device performance of top-emitting organic light-emitting diodes (TEOLEDs) with a thin multi-metal layer stack of nickel/silver/nickel (Ni/Ag/Ni) and aluminum/silver/aluminum (Al/Ag/Al) that were used as the anode and cathode on a flexible substrate is discussed. In particular, Indium-Tin-Oxide (ITO) as an anode electrode has been used recently even though it has some problems for flexible devices. Therefore we suggested that a thin multi-metal layer electrode as a new anode is fabricated instead of ITO anode. It was verified that the ITO-free TEOLEDs showed an enhanced probability of the recombination of the electrons and holes through an improved electron/hole charge balance. We also analyzed the optical and electrical characteristics using the current density, luminance, luminance efficiency, external quantum efficiency (EQE), CIE x, y coordinates, and EL spectra of flexible TEOLED devices were characterized. ITO-free, flexible, green-emitting OLEDs with a low cost and a simple process were demonstrated.
本文讨论了在柔性基板上使用镍/银/镍（Ni/Ag/Ni）和铝/银/铝（Al/Ag/Al）的薄多金属层堆叠作为阳极和阴极的顶发射有机发光二极管（TEOLED）的器件性能改进。特别是，氧化铟锡（ITO）作为阳极电极近来虽被使用，但对于柔性器件存在一些问题。因此，我们建议制造一种薄多金属层电极作为新的阳极来替代ITO阳极。结果证实，无ITO的TEOLED通过改善电子/空穴电荷平衡，显示出电子和空穴复合概率的提高。我们还使用电流密度、亮度、发光效率、外量子效率（EQE）、CIE x、y坐标对柔性TEOLED器件的光学和电学特性进行了分析，并对其EL光谱进行了表征。展示了低成本且工艺简单的无ITO、柔性、绿色发光OLED。
