Interface effects on titanium growth on graphene
arXiv:2204.09669 · doi:10.1088/2053-1583/acf22e
Abstract
Poor quality interfaces between metal and graphene cause non-linearity and impair the carrier mobility in graphene devices. Here, we use aberration corrected scanning transmission electron microscopy to observe hexagonally close-packed Ti nano-islands grown on atomically clean graphene, and establish a 30° epitaxial relationship between the lattices. Due to the strong binding of Ti on graphene, at the limit of a monolayer, the Ti lattice constant is mediated by the graphene epitaxy, and compared to bulk Ti, is strained by ca. 3.7% to a value of 0.306(3) nm. The resulting interfacial strain is slightly greater than what has been predicted by density functional theory calculations. Our early growth stage investigations also reveal that, in contrast to widespread assumptions, Ti does not fully wet graphene but grows initially in clusters with a thickness of 1-2 layers. Raman spectroscopy implies charge transfer between the Ti islands and graphene substrate.
11 pages, 5 figures
References in corpus (8)
- Uniaxial Strain in Graphene by Raman Spectroscopy: G peak splitting, Gruneisen Parameters and Sample Orientation
- Mixed-Dimensional van der Waals Heterostructures
- Optical Separation of Mechanical Strain from Charge Doping in Graphene
- Negative Thermal Expansion Coefficient of Graphene Measured by Raman Spectroscopy
- Evidence of the role of contacts on the observed electron-hole asymmetry in graphene
- Single-atom spectroscopy of phosphorus dopants implanted into graphene
- Increasing the active surface of titanium islands on graphene by nitrogen sputtering
- Revealing the multi-bonding state between hydrogen and graphene-supported Ti clusters