Crescimento de heteroestruturas de carbono sp2 e MoS2 por deposição química a vapor

Abstract

In this work, we used the CVD (chemical vapor deposition) method to obtain sp2 carbon and MoS2 heterostructures (HSs). Unlike what is most studied – HSs obtained through the transfer of materials to another substrate – here we grew MoS2 crystals directly on the carbon film (GR). First, we obtained sp2 carbon films by CVD and, to avoid the transfer process, the GR was grown directly on the Si/SiO2 substrate, without the use of metal catalyst. Therefore, the synthesis process is different and takes longer. After parameterizing this growth, we moved on to the next step, which is the growth of MoS2 directly on the carbon material. The materials were characterized by resonant Raman spectroscopy, since the normal vibration modes of two-dimensional crystals are sensitive to environmental variations, such as stretching or doping. We conclude that the interaction between materials in HS is more pronounced when MoS2 is directly grown on the GR. Shifts of the first-order A1´ peak of MoS2 indicate that there is a ntype doping of the TMD (transition metal dichalcogenide) in the HS. In carbon, the Raman G and 2D peaks shift, implying doping or stretching of the hexagonal lattice.