From graphene to graphene-based gas sensors operating in environmental conditions

The thesis work is focused on two major items: 1. growth and characterization of graphene films; 2. test of the material sensing properties towards analytes by employing graphene-based chemi-resistors as transducers. The mostly exploited techniques for the graphene production are Liquid Phase Exfoliation (LPE) and Chemical Vapor Deposition. The material characterizations performed through Raman spectroscopy, Atomic Force Microscopy and Transmission Electron Microscopy are presented. The experimental results allow to argue the morphological and structural nature of such prepared materials. The issue regarding the GR defects is also addressed with the purpose to better understand the strong sensitive of material in the sensing field. The sensors, operating at room temperature and pressure as well as in presence of humidity, are tested towards several analytes, such as NO2, H2 and NH3. The sensors are calibrated in the sub-ppm range of NO2 so that the devices result to be particularly appealing as graphene-based sensors for NO2 operating in wet environment.