Improvement of stability and response to nitrogen dioxide of graphene on SiC sensors after functionalization with nickel phthalocyanine.

Freddi S., Casotto A., Zanotti M., Drera G., Pagliara S., Schio L., Verdini A., Floreano L., Sangaletti L.
  Venerdì 16/09   09:00 - 13:30   Aula L - Christa Mc Auliffe   VI - Fisica applicata, acceleratori e beni culturali   Presentazione
2D materials show unique physical and chemical properties which can be exploited in several applications, including gas sensors. Among 2D materials, graphene has attracted particular interest, and it has started to be used as a sensing element to detect concentration of gases released in the environment. Nevertheless, pristine graphene does not show remarkable performances as gas sensor, and functionalization is often required to improve its sensing capability. Nickel phthalocyanine powder has been sublimated in UHV with a custom-made thermal evaporator and deposited on a monolayer graphene on silicon carbide substrate. After characterization through Raman, XPS and AFM measurements, the functionalized sample and a pristine graphene layer have been settled on a properly designed platform, able to monitor the sensor response simultaneously, allowing us to directly compare the performances of the sensors under the same working condition. Exposures to ammonia and nitrogen dioxide have been carried out, disclosing an improvement of the sensor response after functionalization, as well as a higher stability of the functionalized layer in the case of nitrogen dioxide exposures.