Exploiting the properties of two-dimensional crystals requires a mass production method able to produce heterostructures of arbitrary complexity on any substrate. Solution processing of graphene allows simple and low-cost techniques such as inkjet printing to be used for device fabrication. However, the available printable formulations are still far from ideal as they are either based on toxic solvents, have low concentration, or require time-consuming and expensive processing. In addition, none is suitable for thin-film heterostructure fabrication due to the re-mixing of different two-dimensional crystals leading to uncontrolled interfaces and poor device performance. Here, we show a general approach to achieve inkjet-printable, water-based, two-dimensional crystal formulations, which also provide optimal film formation for multi-stack fabrication. We show examples of all-inkjet-printed heterostructures, such as large-area arrays of photosensors on plastic and paper and programmable logic memory devices. Finally, in vitro dose-escalation cytotoxicity assays confirm the biocompatibility of the inks, extending their possible use to biomedical applications.

利用二维晶体的特性需要一种能够在任何基板上产生任意复杂度的异质结构的批量生产方法。石墨烯的固溶处理允许将简单且低成本的技术（例如喷墨印刷）用于设备制造。然而，可用的可印刷制剂仍远非理想，因为它们基于有毒溶剂，浓度低或需要耗时且昂贵的处理。另外，由于不同的二维晶体的重新混合导致界面不受控制和不良的器件性能，因此没有一种适合于薄膜异质结构的制造。在这里，我们展示了一种通用方法来实现可喷墨打印的水基二维晶体配方，这也为多叠层制造提供了最佳的成膜性。我们展示了全喷墨打印的异质结构的示例，例如塑料和纸张上的光电传感器的大面积阵列以及可编程逻辑存储设备。最后，体外剂量递增细胞毒性试验证实了墨水的生物相容性，将其可能的用途扩展到了生物医学领域。