Highly Conductive Nitrogen-Doped Vertically Oriented Graphene toward Versatile Electrode-Related Applications.

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Direct growth of vertically oriented graphene (VG) on glass is desirable for transparent electrodes.
• Low-temperature growth on soda-lime glass yields poor quality graphene with high defects and low conductivity.
• Existing methods struggle to achieve high-quality graphene on insulating substrates.

Purpose of the Study:

• To develop a method for growing high-quality VG on glass substrates at higher temperatures.
• To improve the electrical conductivity and crystalline quality of VG films.
• To explore the application of N-doped VG in switchable windows and as electrocatalysts.

Main Methods:

• Utilized radio-frequency plasma-enhanced chemical vapor deposition (rf-PECVD) on high borosilicate glass substrates.
• Employed a methane/acetonitrile precursor mixture for nitrogen doping.
• Investigated the effect of higher growth temperatures (enabled by the substrate) on graphene quality.

Main Results:

• Achieved significantly improved crystalline quality and reduced defect density in VG films.
• Obtained nitrogen-doped VG films with sheet resistance as low as ~2.3 kΩ·sq⁻¹ at 88% transmittance.
• Demonstrated uniform 30-inch-scale production of N-doped graphene glass.

Conclusions:

• High borosilicate glass enables higher growth temperatures for superior VG quality via rf-PECVD.
• Nitrogen doping effectively enhances the electrical conductivity of VG films.
• The developed N-doped VG films are suitable for large-scale applications like switchable windows and electrocatalytic hydrogen evolution.