Seed-Initiated Synthesis and Tunable Doping Graphene for High-Performance Photodetectors

Due to the promising utilizations in nanoelectronics, doping-tunable graphene is paid extensive attentions. Nevertheless, a harmless approach to dope/co-dope graphene in a controllable and easy way with low cost is still unattainable. Herein, through seeding of 0D N & S dual-doped graphene quantum dots (N & S dual-doped GQDs) on a catalytic substrate and then dynamic chemical vapor deposition (CVD), a monolayered dual-doped graphene film is demonstrated. The concentrations of dopants in graphene are strictly discerned in accordance with preliminary seeding for dual-doped GQDs. Through the monitoring of growing process, the research elucidates the growth mechanism of the graphene, and unveils that dual-doped GQDs can serve as the nucleation centers for creating doped-graphene films by 2D epitaxial growth and thus graphene with designed dopant concentration can be obtained. Finally, the photodetector built on N & S dual-doped graphene film is found to perform satisfactorily, accompanying high detectivity (≈1.42 × 10¹⁰ cm Hz^1/2 W⁻¹) and responsivity (61 mA W⁻¹), at wavelength of 1550 nm. The research proposes a dexterous approach for synthesizing tunably doped graphene films by the combination of locally controlled nucleation seeds and in situ CVD, which lays the foundation for applying graphene in industries of photonic and electronic devices.