<p>Uniform quantum dot (QD) films, especially those with well-defined edges, are crucial for high-performance quantum dot light-emitting diode (QLED) devices. However, current solution strategies have suffered from either the inhomogeneity or irregular edges aroused by the uncontrollable fluid dynamics during liquid transfer onto and/or dewetting on the target substrate. Here, we developed a helical fibrous liquid bridge approach to transfer liquid homogeneously across the entire printing area, enabling a uniform QD film with well-defined edges over an area up to 32 cm<sup>2</sup>. The helical fiber, with a thread width of approximately 120 μm, facilitates periodic anchoring of the liquid bridge during the whole liquid transfer process, leading to a homogeneous liquid film. Worth noting is that the as-formed quasi-steady meniscus at the liquid bridge edge helps suppress variation in edge curvature, whereby the pinning sites of the tri-phase contact line are liable to move along a defined linear edge. By this virtue, we demonstrated a high-performance red QLED with a peak luminance of 2.4 × 10<sup>5</sup> cd/m<sup>2</sup> and a peak EQE of 20.8%. The result offers an alternative facile approach for making uniform QD films with well-defined edges, which facilitates further device integration.</p> Graphical Abstract <p></p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Uniform Quantum Dot Film with Well-Defined Edges by A Helical Fibrous Liquid Bridge: Toward High-Performance Light-Emitting Diode

  • Xiaoxun Li,
  • Huanhuan Deng,
  • Zheng Xiao,
  • Zhongyu Shi,
  • Ran Sun,
  • Yunqi Bai,
  • Min Zhang,
  • Lei Jiang,
  • Huan Liu

摘要

Uniform quantum dot (QD) films, especially those with well-defined edges, are crucial for high-performance quantum dot light-emitting diode (QLED) devices. However, current solution strategies have suffered from either the inhomogeneity or irregular edges aroused by the uncontrollable fluid dynamics during liquid transfer onto and/or dewetting on the target substrate. Here, we developed a helical fibrous liquid bridge approach to transfer liquid homogeneously across the entire printing area, enabling a uniform QD film with well-defined edges over an area up to 32 cm2. The helical fiber, with a thread width of approximately 120 μm, facilitates periodic anchoring of the liquid bridge during the whole liquid transfer process, leading to a homogeneous liquid film. Worth noting is that the as-formed quasi-steady meniscus at the liquid bridge edge helps suppress variation in edge curvature, whereby the pinning sites of the tri-phase contact line are liable to move along a defined linear edge. By this virtue, we demonstrated a high-performance red QLED with a peak luminance of 2.4 × 105 cd/m2 and a peak EQE of 20.8%. The result offers an alternative facile approach for making uniform QD films with well-defined edges, which facilitates further device integration.

Graphical Abstract