Fast and Patternable Synthesis of Graphene and Transition Metal Dichalcogenide Materials Via Laser Annealing on Insulating Substrates

The two-dimensional layered materials such as graphene and transition metal dichalcogenides (TMDs) have recently attracted much interest due to their astonishing properties under reduced dimensionality. Exceptional physical properties including ultra high mobility with high electrical conductivity for graphene and transition from indirect to direct bandgap showing excellent field effect behavior in TMD’s; open up a wide range of potential applications in optoelectronics, energy harvesting, Li-ion batteries and supercapacitors. However, the synthesis approach by CVD does not allow pattern and requires the use of high temperature processes restricting the use of substrates that can sustain such temperatures. Furthermore, the films have to be transferred to an additional substrate due to the damage caused to the original substrate used for synthesis. Therefore, further improvement of the synthesis methods is an important step to pursue. Here, we use a laser approach to induce simultaneously grow and pattern of graphene, WSe₂ and MoSe₂ directly on insulating substrates ready for device fabrication without the necessity of additional transfer processes. Raman and X-ray Photoelectron Spectroscopies supported by TEM observations to confirm the synthesis and crystallinity of the synthesized films. The process can be tuned to achieve a controllable number of atomic layers of the synthesized material. Moreover, this approach can be extended to the synthesis of other materials. This laser annealing assisted method develops a new approach that is fast, cheap and patternable giving a step forward on the technology development for practical applications.