High sensitive quasi freestanding epitaxial graphene gassensor on 6H-SiC

TL;DR

This paper demonstrates that quasi freestanding epitaxial graphene on 6H-SiC exhibits significantly enhanced sensitivity to NO₂ gas compared to traditional epitaxial graphene, with potential for ultra-sensitive gas detection.

Contribution

The study reveals that quasi freestanding epitaxial graphene has a sixfold increase in NO₂ sensitivity due to its Fermi energy position, advancing gas sensor technology.

Findings

Quasi freestanding epitaxial graphene shows 6x NO₂ sensitivity.

Both sensors detect below 1 ppb NO₂.

Negligible response to N₂, NH₃, and CO.

Abstract

We have measured the electrical response to NO$_2$, N$_2$, NH$_3$ and CO for epitaxial graphene and quasi freestanding epitaxial graphene on 6H-SiC substrates. Quasi freestanding epitaxial graphene shows a 6 fold increase in NO2 sensitivity compared to epitaxial graphene. Both samples show a sensitivity better than the experimentally limited 1 ppb. The strong increase in sensitivity of quasi freestanding epitaxial graphene can be explained by a Fermi-energy close to the Dirac Point leading to a strongly surface doping dependent sample resistance. Both sensors show a negligible sensitivity to N$_2$, NH$_3$ and CO.