Growth and electrical properties of n-type monolayer sulfur-doped graphene film in air

Theoretical calculations demonstrate that sulfur doping is a promising n-type doping method to modulate the electrical properties of graphene. However, as far as we know, the reported sulfur-doped graphene (SG) films have all shown the p-type behavior in air, where doped sulfur atoms have been mainly in the form of thiophene-like S-C structures. The reason is that thiophene-like S-C structures as donors cannot fully neutralize the effect of adsorbed oxygen/water molecules as acceptors on the SG film. In this study, the monolayer SG film has been synthesized by the chemical vapor deposition method, where the doped sulfur atoms are mainly in the form of S-H structures. The electrical studies reveal that the electron concentration of SG film is similar to 1.1 x 10(12) cm(-2), indicating the typical n-type behavior in air; moreover, its mobility is as high as similar to 753 cm(2) V(-1)s(-1), which is obviously higher than those of reported SG films. To the best of our knowledge, it is the first time to obtain the n-type SG film in air. The good performance of n-type SG film can be attributed that S-H shows a stronger electron donor ability and lower carrier scattering than does thiophene-like S-C. This study is expected to not only promote the potential applications of SG film, but also benefit the fundamental understanding of effect mechanism of sulfur structures on the properties of SG film. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Theoretical calculations suggest that sulfur doping can modulate the electrical properties of graphene, with sulfur-hydrogen structures being more effective at n-type doping than thiophene-like sulfur-carbon structures. The synthesized monolayer sulfur-doped graphene film exhibits n-type behavior in air, with a high electron concentration and mobility, surpassing previous reports. This study not only demonstrates the potential applications of sulfur-doped graphene films, but also enhances our understanding of the impact of sulfur structures on their properties.