Kovalska Evgeniya, Pavlov Ihor, Deminskyi Petro, Baldycheva Anna, Ilday F Ömer, Kocabas Coskun
Laboratory of Smart Materials and Devices, Department of Physics, and Ultrafast Optics and Lasers Laboratory, Department of Physics, Bilkent University, Ankara 06800, Turkey.
Department of Engineering and Centre for Graphene Science, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF, U.K.
ACS Omega. 2018 Feb 28;3(2):1546-1554. doi: 10.1021/acsomega.7b01853. Epub 2018 Feb 6.
The range of applications of diverse graphene-based devices could be limited by insufficient surface reactivity, unsatisfied shaping, or null energy gap of graphene. Engineering the graphene structure by laser techniques can adjust the transport properties and the surface area of graphene, providing devices of different nature with a higher capacitance. Additionally, the created periodic potential and appearance of the active external/inner/edge surface centers determine the multifunctionality of the graphene surface and corresponding devices. Here, we report on the first implementation of nonlinear laser lithography (NLL) for multilayer graphene (MLG) structuring, which offers a low-cost, single-step, and high-speed nanofabrication process. The NLL relies on the employment of a high repetition rate femtosecond Yb fiber laser that provides generation of highly reproducible, robust, uniform, and periodic nanostructures over a large surface area (1 cm/15 s). NLL allows one to obtain clearly predesigned patterned graphene structures without fabrication tolerances, which are caused by contacting mask contamination, polymer residuals, and direct laser exposure of the graphene layers. We represent regularly patterned MLG (p-MLG) obtained by the chemical vapor deposition method on an NLL-structured Ni foil. We also demonstrate tuning of chemical (wettability) and electro-optical (transmittance and sheet resistance) properties of p-MLG by laser power adjustments. In conclusion, we show the great promise of fabricated devices, namely, supercapacitors, and Li-ion batteries by using NLL-assisted graphene patterning. Our approach demonstrates a new avenue to pattern graphene for multifunctional device engineering in optics, photonics, and bioelectronics.
各种基于石墨烯的器件的应用范围可能会受到石墨烯表面反应性不足、成型不理想或能隙为零的限制。通过激光技术对石墨烯结构进行工程设计，可以调整石墨烯的传输特性和表面积，为不同性质的器件提供更高的电容。此外，所产生的周期性电势以及活性外部/内部/边缘表面中心的出现决定了石墨烯表面及相应器件的多功能性。在此，我们报告了用于多层石墨烯（MLG）结构化的非线性激光光刻（NLL）的首次实现，它提供了一种低成本、单步且高速的纳米制造工艺。NLL依赖于使用高重复率飞秒Yb光纤激光器，该激光器能够在大面积（1平方厘米/15秒）上生成高度可重复、坚固、均匀且周期性的纳米结构。NLL能够获得预先明确设计的图案化石墨烯结构，而不会出现由接触掩膜污染、聚合物残留以及石墨烯层的直接激光曝光所导致的制造公差。我们展示了通过化学气相沉积法在经NLL结构化的镍箔上获得的规则图案化多层石墨烯（p-MLG）。我们还通过调整激光功率展示了对p-MLG的化学（润湿性）和电光（透射率和薄层电阻）特性的调控。总之，我们展示了利用NLL辅助的石墨烯图案化制造的器件，即超级电容器和锂离子电池的巨大潜力。我们的方法为在光学、光子学和生物电子学中用于多功能器件工程的石墨烯图案化开辟了一条新途径。
