Microwave graphitic nitrogen/boron ultradoping of graphene

Abstract

Insufficient carrier concentration and lack of room temperature ferromagnetism in pristine graphene limit its dream applications in electronic and spintronic chips. While theoretical calculations have revealed that graphitic ultradoping can turn graphene into semiconducting and room temperature ferromagnetic, the exotic set of thermodynamic conditions needed for doping result in defects and functionalities in graphene which end up giving significant electronic scattering. We report our discovery of microwave ultradoping of graphene with N > 30%, B ~ 19%, and co-doping to form BCN phases (B5C73N22, B8C76N16, and B10C77N13). An unprecedented level of graphitic doping ~95% enhances carrier concentration up to ~9.2 × 1012 cm−2, keeping high electronic mobility ~9688 cm2 V−1s−1 intact, demonstrated by field effect transistor measurements. Room temperature ferromagnetic character with magnetization ~4.18 emug−1 is reported and is consistent with our DFT band structure calculations. This breakthrough research on tunable graphitic ultradoping of 2D materials opens new avenues for emerging multi-functional technological applications.