Insights into the Mechanism for Vertical Graphene Growth by Plasma-Enhanced Chemical Vapor Deposition
Artikel i vetenskaplig tidskrift, 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
Författare
Jie Sun
Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik
Tanupong Rattanasawatesun
Student vid Chalmers
Penghao Tang
Beijing University of Technology
Zhaoxia Bi
Lunds universitet
Santosh Pandit
Chalmers, Biologi och bioteknik, Systembiologi
Lisa Lam
Göteborgs universitet
Caroline Wasen
Göteborgs universitet
Malin Erlandsson
Göteborgs universitet
Maria Bokarewa
Göteborgs universitet
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, Biologi och bioteknik, Systembiologi
Danmarks Tekniske Universitet (DTU)
ACS Applied Materials & Interfaces
1944-8244 (ISSN) 1944-8252 (eISSN)
Vol. 14 5 7152-7160Ämneskategorier
Materialkemi
Annan kemi
Den kondenserade materiens fysik
DOI
10.1021/acsami.1c21640
PubMed
35005901