Luo Yu, Wang Chunhui, Wang Li, Ding Yucheng, Li Long, Wei Bin, Zhang Jianhua
State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University , Xi'an 710049, China.
ACS Appl Mater Interfaces. 2014 Jul 9;6(13):10213-9. doi: 10.1021/am501521p. Epub 2014 Jun 20.
High-efficiency organic light-emitting diodes (OLEDs) have generated tremendous research interest. One of the exciting possibilities of OLEDs is the use of flexible plastic substrates, which unfortunately have a mismatching refractive index compared with the conventional ITO anode and the air. To unlock the light loss on flexible plastic, we report a high-efficiency flexible OLED directly fabricated on a double-sided nanotextured polycarbonate substrate by thermal nanoimprint lithography. The template for the nanoimprint process is a replicate from a silica arrayed with nanopillars and fabricated by ICP etching through a SiO2 colloidal spheres mask. It has been shown that with the internal quasi-periodical scattering gratings the efficiency enhancement can reach 50% for a green light OLED, and with an external antireflection structure, the normal transmittance is increased from 89% to 94% for paraboloid-like pillars. The OLED directly fabricated on the double-sided nanotextured polycarbonate substrate has reached an enhancing factor of ∼2.8 for the current efficiency.
高效有机发光二极管（OLED）引起了极大的研究兴趣。OLED令人兴奋的可能性之一是使用柔性塑料基板，不幸的是，与传统的ITO阳极和空气相比，其折射率不匹配。为了解决柔性塑料上的光损失问题，我们报道了一种通过热纳米压印光刻技术直接在双面纳米纹理聚碳酸酯基板上制造的高效柔性OLED。纳米压印工艺的模板是由排列有纳米柱的二氧化硅复制而来，并通过ICP蚀刻穿过SiO2胶体球掩膜制造而成。结果表明，对于绿光OLED，利用内部准周期散射光栅，效率提高可达50%；对于抛物面状柱体，采用外部抗反射结构后，正透射率从89%提高到94%。直接在双面纳米纹理聚碳酸酯基板上制造的OLED的电流效率提高因子达到了约2.8。
