Patterning graphene into nanoribbons (graphene nanoribbons, GNR) allows for tunability in the emerging fields of plasmonic devices in the mid-infrared and terahertz regime. However, the fabrication processes of GNR arrays for plasmonic devices often include a low-throughput electron beam lithography step that cannot be easily scaled to large areas. In this study, we developed a GNR fabrication method using block copolymer (BCP) lithography that takes advantage of the wetting transparency of graphene. One major advantage of this method is that the self-assembled domains of the polystyrene-block-poly(methyl methacrylate) BCP are oriented perpendicularly directly on top of the graphene where they can later serve as an etch mask. Large area (cm2 scale, 3 μm × 3 μm defect-free area) 13–51 nm wide GNR arrays were successfully fabricated using this scalable protocol. This wetting transparency-assisted GNR fabrication method could be useful for high-throughput production of various plasmonic devices, including biosensors, and photodetectors.
Bibliographical noteFunding Information:
This work was supported in part by an NSF CAREER (1150034) award (D.A.), and the NSF-NASCENT Engineering Research Center (Cooperative Agreement No. EEC-1160494). C.J.E. thanks the Welch Foundation (grant # F-1709), DuPont Young Professor Award, 3 M Nontenured Faculty Award for partial financial support. The authors would like to thank Jo Wozniak for designing Fig. 1 and the table of contents graphic. We would also like to thank Prof. Seth R. Bank, Kyle McNicholas, Andrew Briggs, Xiaohan Wang and Chae Bin Kim for helpful discussions. We also appreciate Prof. Ananth Dodabalapur, Dr. Dustin Janes, and Barrett Worley for their input in the early stages of this project. R.K. appreciates the Takenaka Scholarship and Graduate Dean's Prestigious Fellowship Supplement for financial support.
- Block copolymer