蒸發驅動二維材料塗佈形成圖形

Abstract

二維材料，因其獨特的性能以及能從溶液中的塊材前驅物簡單剝離出高品質材料的能力，吸引了研究人員的注意力。為了實現廉價且普及的液體沉積電子產品，必須設計出一種合適的組裝方法，該方法可以保留2D形態並支持複雜的元件幾何形狀。 我們在這裡演示了一種直接從解決方案直接將2D材料沉積到複雜電路中的新方法，而無需在沉積材料後才蝕刻出電路。 通過將液滴限制在二維上，產生了連續的液膜，其程度由楊-拉普拉斯效應和毛細現象、重力的競爭決定。該限制在液滴頂部產生蒸發的方向性，並導致二維薄膜後退。與此同時，流向液滴邊緣的液流會推動石墨烯材料向邊緣移動，進而產生厚度、寬度均勻的1D分布。 所得的1D圖案在毫米級圖形上顯示出微小的寬度和良好的均勻性，非常適合電子設備。我們通過使用石墨烯形成的晶體管來演示複雜電路的形成。

2D materials have captured the attention of researchers due to their unique properties and the ability to produce high-quality material by simple exfoliation from bulk precursors in solution. To realize the vision of cheap and ubiquitous, liquid-deposited electronics, a suitable assembly method has to be devised that retains the 2D morphology and supports complicated device geometries. We here demonstrate a new method of depositing 2D materials into complex circuits directly from solution without the need for post-deposition patterning. By confining a liquid droplet in two dimensions, a continuous liquid film is produced whose extents are determined by the competition of Young-Laplace equation, gravity and capillary force. The confinement produces a preferential direction of evaporative liquid loss on the top of the droplet and results in receding 2D film. Such a receding motion of liquid produces a flow that brings solute to the edge, resulting in deposition of the dispersed 2D material in a well-defined region. The resulting 1D patterns exhibit a microscopic width and good uniformity over millimeter-scale and lend themselves to electrical devices. We demonstrate the formation of complex electrical circuits through when using graphene and transistors formed from graphene/MoS2.