Department of Chemical Engineering and Materials Science and ‡Department of Chemistry, University of California , Davis, California, United States.
ACS Nano. 2015 Feb 24;9(2):1905-12. doi: 10.1021/nn506820d. Epub 2015 Jan 27.
Organic electronics promise to provide flexible, large-area circuitry such as photovoltaics, displays, and light emitting diodes that can be fabricated inexpensively from solutions. A major obstacle to this vision is that most conjugated organic materials are miscible, making solution-based fabrication of multilayer or micro- to nanoscale patterned films problematic. Here we demonstrate that the solubility of prototypical conductive polymer poly(3-hexylthiophene) (P3HT) can be reversibly "switched off" using high electron affinity molecular dopants, then later recovered with light or a suitable dedoping solution. Using this technique, we are able to stack mutually soluble materials and laterally pattern polymer films by evaporation or with light, achieving sub-micrometer, optically limited feature sizes. After forming these structures, the films can be dedoped without disrupting the patterned features; dedoped films have identical optical characteristics, charge carrier mobilities, and NMR spectra as as-cast P3HT films. This method greatly simplifies solution-based device fabrication, is easily adaptable to current manufacturing workflows, and is potentially generalizable to other classes of materials.
有机电子有望提供灵活的大面积电路，例如可以廉价地从溶液中制造的光伏、显示器和发光二极管。这一愿景的主要障碍是，大多数共轭有机材料是可混溶的，这使得基于溶液的多层或微到纳米级图案化薄膜的制造成为问题。在这里，我们证明了典型的导电聚合物聚（3-己基噻吩）（P3HT）的溶解度可以使用高电子亲和力的分子掺杂剂可逆地“关闭”，然后用光或合适的脱掺杂溶液恢复。使用这种技术，我们能够通过蒸发或用光堆叠互溶性材料并对聚合物薄膜进行横向图案化，实现亚微米、光学限制的特征尺寸。形成这些结构后，可以对薄膜进行脱掺杂而不会破坏图案化特征；脱掺杂的薄膜与原样 cast 的 P3HT 薄膜具有相同的光学特性、电荷载流子迁移率和 NMR 谱。该方法极大地简化了基于溶液的器件制造，易于适应当前的制造工作流程，并且可能推广到其他材料类别。
