@article{Zou2023, 
author = {Mingzhi Zou and Weiming Liu and Yue Yu and Shanshan Wang and Bo Xu and Liu Qian and Tianze Tong and Jin Zhang},
title = {Direct growth of globally aligned graphene nanoribbons on reconstructed sapphire substrate using PECVD},
year = {2023},
journal = {Nano Research},
volume = {16},
number = {1},
pages = {62-69},
keywords = {sapphire, graphene nanoribbon (GNR), global alignment, insulating substrates, plasma enhanced chemical vapor deposition (PECVD)},
url = {https://www.sciopen.com/article/10.1007/s12274-022-4797-1},
doi = {10.1007/s12274-022-4797-1},
abstract = {Graphene nanoribbons (GNRs) are regarded as an ideal candidate for beyond-silicon electronics. However, synthesis of aligned GNR arrays on insulating substrates with high efficiency is challenging. In this work, we develop a facile strategy, involving KOH pre-treatment and high-temperature annealing, to construct parallel steps on the two-fold symmetry a-plane sapphire substrate. Horizontal GNRs as narrow as 15.1 nm with global alignment across a region of 20 mm2 are then grown on the step edge-enriched substrate through plasma enhanced chemical vapor deposition (PECVD) method. GNRs align well along the atomic steps on sapphire ([ 11¯00] direction) with their widths and densities swiftly adjustable by step morphology modification on substrate surface. A step-edge confined growth mechanism is proposed, attributing the constraint on the nanoribbon broadening to a relatively low growth temperature in PECVD, which restrains the activation energy to suppress GNRs across step edges on sapphire and prevents detrimental nanoribbon widening. The results provide a new perspective for scalable synthesizing well aligned nanoribbons of other two-dimensional materials.}
}