Improvement of synthesized graphene structure through various solvent liquids at low temperatures by chemical vapor deposition method

Abstract

There is a great interest in producing large-area graphene films at low temperatures by chemical vapor deposition for many applications. In this paper, experimental studies are conducted to improve of graphene quality with various liquid precursors at low temperatures by chemical vapor deposition. Here we produced graphene using new materials, methanol, n-butanol, n-Heptane and cyclohexane, as a liquid precursor in order to find the best liquid precursors at low temperature. This study tries to find the range of the growth temperature in which graphene was grown using each liquid precursor. Size of graphene domains, the number of graphene layers and their quality were measured at each temperature using each precursor. Graphene domains produced with cyclohexane were larger than the other precursors, and it was bilayer graphene at a low temperature of its range. In this study, optical microscope, Atomic Force Microscope, Field Emission Scanning Electron Microscopy and Raman spectroscopy were used to characterize the quality of graphene, size of graphene domain and the number of graphene layers. Our findings reveal that precursor with large and complicated structure must decompose to smaller and simpler material to produce graphene. Also, we consider the effect of oxygen on the quality of graphene at different temperatures for the first time and found that the effect of oxygen in high growth temperature is negligible, but at low temperature, not only oxygen can affect on the graphene grown but also this element can produce reduced graphene oxide at low temperatures.