| dc.description.abstract | Carrier mobility in graphene often affect the electronic properties, because of charge scattering, impurities, and polymer residues on the substrate. In order to resolve this problem, we use a self-assembled monolayer on the substrate which used to improve the electronic properties of graphene and avoids the influence of substrate factors, so that the graphene maintains the most basic properties.
In this experiment, there were four different fluoric solutions be tested, the results show 2 μl FDTS + 100 ml toluene was the optimal parameters between different fluoric solution ratio, then we uses dip-coating and spin-coating to modify the substrate, respectively. Thses two ways can modify the substrate in a short period of time, and using dry transfer to transfer graphene on the substrate. This results reveal that using F-SAM improves the surface roughness of the substrate from 2.27 nm to 0.29 nm. The electron mobility can improve from 894.6 cm2/Vs to 1588cm2/Vs, about 1.77 times higher than the unmodified substrate by using Hall measurement. This results can be attributed to the following factors. First and foremost, reducing the surface roughness of the substrate can reduce the transfer graphene under stress rupture and wrinkle structure. On the other hand, the half suspended structure generated by the long chain molecules of a self-assembled monolayer can prevent the carrier scattering caused by the substrate on the graphene and affect its transmission. In addition, the research also exhibited that dry transfer can reduce the overall roughness of the film by 87.8% compared to wet transfer, and therefore the carrier mobility has a rising tendency. Finally, we infer that the MoS2 on F-SAM maybe transferred to p-doping influenced on/off ratio and carry mobility will decrease, and therefore the mechanism of applying F-SAM modified substrate to the interfacial polarization of 2D semiconductor materials can be further verified. This study will get a deeper understanding of the electronic structure adjustment and device integration of 2D materials in the future. | en_US |