High-quality nitrogen-doped graphene films synthesized from pyridine via two-step chemical vapor deposition

Abstract

Modulation of the electrical properties of graphene is of significant importance in advancing graphene electronics: it can be achieved by a Fermi level shift induced by electron acceptor/donor doping. Suitable doping methods involving low-temperature processes and offering long-term stability are imperative to practical applications for such materials. Here, we demonstrate a two-step chemical vapor deposition (CVD) technique for direct synthesis of N-doped graphene film from a pyridine feed-stock at 300 °C under ambient pressure. We extended the synthesis—classified into nucleation and lateral growth steps—by controlling the carbon partial pressure in the processing gases. This led to large-area, continuous N-doped graphene films of excellent quality with full surface coverage: for example, a film size of 2 in2, optical transmittance of 97.6%, and electron mobility of 1400 cm2 V−1 s−1. Our modified CVD method is expected to facilitate the direct synthesis of N-doped graphene in device manufacturing processes toward practical applications while keeping the underlying devices intact.