جستجوی مقالات مرتبط با کلیدواژه « مشخصه یابی سطحی » در نشریات گروه « شیمی »

Graphene as a two-dimensional material of carbon atoms in a honeycomb lattice show that this substance is applicable in nano- and micro-scale electrical devices. In this research, small graphene flakes and large area graphene were produced through micromechanical exfoliation and chemical vapor deposition (CVD), respectively. They were further transferred on silicon nitride (SiN) insulating substrates that were previously decorated by electrical contacts. These contacts were obtained by direct and reduced photolithography. Surface characterization with optical and atomic force microscopies and Raman spectroscopy determined the number, extension, continuity of layers and purity of the surface. Current-voltage and resistance measurements were carried out via dynamic and static 4-point probes, respectively. The effect of type and dimensions of the contacts, purity of the surface and the number of graphene layers were explored. Our results demonstrated linear and nonlinear voltage behavior in single-layer and multi-layer graphene sheets, respectively.