Reducing the Metal-Graphene Contact Resistance through Laser-Induced Defects.
ACS Appl Electron Mater
; 6(7): 4883-4890, 2024 Jul 23.
Article
em En
| MEDLINE
| ID: mdl-39070088
ABSTRACT
Graphene has been extensively studied for a variety of electronic and optoelectronic applications. The reported contact resistance between metal and graphene, or rather its specific contact resistance (R C), ranges from a few tens of Ω µm up to a few kΩ µm. Manufacturable solutions for defining ohmic contacts to graphene remain a subject of research. Here, we report a scalable method based on laser irradiation of graphene to reduce the R C in nickel-contacted devices. A laser with a wavelength of l = 532 nm is used to induce defects at the contact regions, which are monitored in situ using micro-Raman spectroscopy. Physical damage is observed using ex situ atomic force and scanning electron microscopy. The transfer length method (TLM) is used to extract R C from back-gated graphene devices with and without laser treatment under ambient and vacuum conditions. A significant reduction in R C is observed in devices where the contacts are laser irradiated, which scales with the laser power. The lowest R C of about 250 Ω µm is obtained for the devices irradiated with a laser power of 20 mW, compared to 900 Ω µm for the untreated devices. The reduction is attributed to an increase in defect density, which leads to the formation of crystallite edges and in-plane dangling bonds that enhance the injection of charge carriers from the metal into the graphene. Our work suggests laser irradiation as a scalable technology for R C reduction in graphene and potentially other two-dimensional materials.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article