Ultrafast Laser Patterning of OLEDs on Flexible Substrate for Solid-state Lighting
Ultrafast Laser Patterning of OLEDs on Flexible Substrate for Solid-state Lighting
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DOI：
10.2961/jlmn.2009.03.0014
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发表时间：
2009-12-01
影响因子：
1.1
通讯作者：
Knowles, Martyn
中科院分区：
文献类型：
--
作者：
Karnakis, Dimitris;Kearsley, Andrew;Knowles, Martyn
柔性箔上有机LED技术的快速发展有望为智能照明应用提供薄、轻、省电的光源。用于显示应用的玻璃上的OLED的激光图案化已被广泛报道。然而，很少有报道讨论柔性衬底上的OLED图案化，这提出了一个新的光学工程挑战。我们在这里的目标是量化皮秒激光在这一应用中的潜力，并确定用于大面积选择性OLED电极图案化的强大的激光工艺窗口。这应该包括：(I)在阻挡层堆叠上完全去除130 nm厚的ITO阳极，以及(Ii)在180 nm厚的LEP/PEDOT：PSS活性有机层上完全去除100 nm厚的Ba/Al阴极，同时保持所有底层完好无损。532 nm和355 nm的详细激光烧蚀研究表明，PS激光通过提供精细的分辨率，独特地促进了卷到卷OLED的制造。将讨论损坏阈值、工艺质量和工艺速度限制。仔细的陨石坑检查表明，对于给定的涂层厚度，激光脉冲宽度的选择比波长更重要。光机械应力诱导的烧蚀机制被认为是这一过程的关键，并且可以实现无碎屑的低温图案化。
Rapid developments in the organic LED technology on flexible foils promise to deliver thin, lightweight and power-efficient light sources for intelligent lighting applications. Laser patterning of OLEDs on glass for display applications has been widely reported. However, fewer reports discuss patterning of OLEDs on flexible substrates, which presents a novel optical engineering challenge. Our aim here is to quantify the potential of picosecond lasers for this application and determine a robust laser process window for large area selective OLED electrode patterning. This should involve the complete removal of (i) 130 nm thick ITO anode on a barrier layer stack and (ii) 100 nm thick Ba/Al cathode on 180 nm thick LEP/PEDOT:PSS active organic layers while leaving intact all underlying layers. Detailed laser ablation studies at 532 and 355 nm reveal that ps lasers uniquely facilitate roll-to-roll OLED manufacturing by providing fine resolution. Damage thresholds, process quality and process speed limitations will be discussed. Careful crater examination reveals that the choice of laser pulse duration is more important than wavelength for a given layer thickness. A photomechanical stress-induced ablation mechanism is believed to be key for this process and debris-free, low temperature patterning can be achieved.