Insights into the Mechanism for Vertical Graphene Growth by Plasma-Enhanced Chemical Vapor Deposition
Journal article, 2022
Vertically oriented graphene (VG) has attracted attention for years, but the growth mechanism is still not fully revealed. The electric field may play a role, but the direct evidence and exactly what role it plays remains unclear. Here, we conduct a systematic study and find that in plasma-enhanced chemical vapor deposition, the VG growth preferably occurs at spots where the local field is stronger, for example, at GaN nanowire tips. On almost round-shaped nanoparticles, instead of being perpendicular to the substrate, the VG grows along the field direction, that is, perpendicular to the particles' local surfaces. Even more convincingly, the sheath field is screened to different degrees, and a direct correlation between the field strength and the VG growth is observed. Numerical calculation suggests that during the growth, the field helps accumulate charges on graphene, which eventually changes the cohesive graphene layers into separate three-dimensional VG flakes. Furthermore, the field helps attract charged precursors to places sticking out from the substrate and makes them even sharper and turn into VG. Finally, we demonstrate that the VG-covered nanoparticles are benign to human blood leukocytes and could be considered for drug delivery. Our research may serve as a starting point for further vertical two-dimensional material growth mechanism studies.
nanoparticles
2D materials
vertical graphene
plasma-enhanced chemical vapor deposition
GaN nanowires
Author
Jie Sun
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Tanupong Rattanasawatesun
Student at Chalmers
Penghao Tang
Beijing University of Technology
Zhaoxia Bi
Lund University
Santosh Pandit
Chalmers, Biology and Biological Engineering, Systems and Synthetic Biology
Lisa Lam
University of Gothenburg
Caroline Wasen
University of Gothenburg
Malin Erlandsson
University of Gothenburg
Maria Bokarewa
University of Gothenburg
Jichen Dong
Ulsan National Institute of Science and Technology (UNIST)
Feng Ding
Ulsan National Institute of Science and Technology (UNIST)
Fangzhu Xiong
Beijing University of Technology
Ivan Mijakovic
Chalmers, Biology and Biological Engineering, Systems and Synthetic Biology
Technical University of Denmark (DTU)
ACS Applied Materials & Interfaces
1944-8244 (ISSN) 1944-8252 (eISSN)
Vol. 14 5 7152-7160Subject Categories
Materials Chemistry
Other Chemistry Topics
Condensed Matter Physics
DOI
10.1021/acsami.1c21640
PubMed
35005901