Direct Growth Graphene Via Atmospheric Pressure Chemical Vapour Deposition

The integration of graphene in field-effect transistor (FET) has aroused tremendous attention in the field of sensor technology, particularly for electronic biosensors. However, transferring graphene from metal substrates has destructive effects on the electrical characteristics of the graphene film, leading to severe impurities and defects. Here, we investigated a new approach of technique to synthesis direct- growth semiconducting graphene via atmospheric pressure chemical vapour deposition (APCVD) method. In this study we observe the effects of different reaction times, carbon concentrations and temperatures on the carbon arrangement in graphene. The synthesised graphene was characterised by Raman spectroscopy and field emission scanning electron microscopy (FESEM) to observe the quality of graphene formation. From the Raman analysis, the I2D/IG ratio < 1 indicates the formation of graphene in multiple layers. The ID /IG ratio < 1 was also observed, indicating that the graphene has less disorder of defects. Based on the electrical measurement of the material at estimated distance of 250 μm, a higher I2D/IG ratio leads to a higher resistance. Full width at half maximum (FWHM) of 2D band shows graphene with the highest I2D/IG ratio has the lowest value of FWHM. As the conclusion, these directly grown semiconducting graphene layers can be efficiently integrated into biosensors without any complex post-treatment process.