Pulsed laser co-deposition of carbon and boron for boron-doped graphene synthesis
Résumé
The introduction of dopants, such as boron, into the graphene network, is essential for many applications (electrochemistry, sensors, photovoltaics, catalysis, etc.). Many preparation routes have been investigated for B-doped graphene (BG) films: CVD, chemical reactions between graphene or graphene oxide with boron precursors, hydrothermal and solvothermal processes, arc discharge, high temperature sublimation of highly B-doped SiC and B4C thermal decomposition. Another way consists in pulsed laser co-ablation of C and B solid sources followed by rapid thermal heating of the B-doped carbon film deposited on a metal catalyst, to obtain BG layers. The objective is to achieve a better control of boron concentration in the films.
Here, we use for the first time pulsed laser co-ablation for the synthesis of B-doped graphene layers. Amorphous a-C:B films, containing 2%at. boron, 10 nm thick, are synthetized by nanosecond pulsed laser deposition on a Ni thin film (60 nm thick) previously deposited on a SiO2 substrate. Rapid Thermal Annealing is performed at 1100°C during 2’ with a heating rate of 15°C/s and a cooling rate of 1°C/s. Raman, XPS, FEG-SEM and AFM characterizations allow to determine the nature, composition and morphology of the BG films. The results confirm the fabrication of bi-trilayers boron doped graphene films with the same boron doping level (2%at) as the starting material. Our results pave a new way for boron doped graphene synthesis using laser processing.