Abstract In our previous research, we found that the laser induction process on commercially available polyimide sheets is a cost-effective method for the formation of porous graphene that can be subsequently fabricated into mechanically flexible devices. Here we study the parameters required for the formation of varied laser-induced graphene (LIG) morphologies by tuning the laser radiation energy. It was found that a critical fluence point of ∼5 J/cm2 is needed to initiate the carbonization process regardless of the laser power. When increasing the radiation energy, the physical formation of LIG follows a fluid dynamics process in that the morphology of the LIG progressively changes from sheets to fibers and finally to droplets. We then demonstrate that a morphology of LIG nanomaterial, LIG fibers (LIGF), can be generated by this one-step laser photothermolysis process at a radiation energy >40 J/cm2. The LIGF are hollow with a LIG wall and form vertically aligned fibers up to 1 mm in height. Microsupercapacitor (MSC) devices fabricated from LIGF and LIGF-LIG hybrids show 2× the specific areal capacitance over MSCs made entirely from LIG, thereby underscoring the potential for LIGF in flexible device applications.

中文翻译：

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激光诱导石墨烯纤维

摘要 在我们之前的研究中，我们发现在市售聚酰亚胺片上的激光感应工艺是一种具有成本效益的方法，可用于形成多孔石墨烯，随后可将其制造成机械柔性器件。在这里，我们通过调整激光辐射能量来研究形成各种激光诱导石墨烯 (LIG) 形态所需的参数。发现无论激光功率如何，都需要～5 J/cm2 的临界注量点来启动碳化过程。当增加辐射能量时，LIG 的物理形成遵循流体动力学过程，因为 LIG 的形态逐渐从片状变为纤维，最后变为液滴。然后，我们证明了 LIG 纳米材料、LIG 纤维（LIGF）的形态，可以通过这种一步激光光热分解过程以>40 J/cm2 的辐射能量产生。LIGF 是空心的，带有 LIG 壁，形成垂直排列的纤维，高度可达 1 毫米。由 LIGF 和 LIGF-LIG 混合体制成的微型超级电容器 (MSC) 器件的比表面积是完全由 LIG 制成的 MSC 的 2 倍，从而强调了 LIGF 在柔性器件应用中的潜力。