Ultrasensitive gas sensors based on vertical graphene nanowalls/SiC/Si Heterostructure
Journal
ACS Sensors
Journal Volume
4
Journal Issue
2
Pages
406-412
Date Issued
2019
Author(s)
Chen, Kuei Hsien
Abstract
Gas sensors, which play an important role in the safety of human life, cover a wide range of applications including intelligent systems and detection of harmful and toxic gases. It is known that graphene is an ideal and attractive candidate for gas sensing due to its high surface area and excellent mechanical, electrical, optical, and thermal properties. However, in order to fully realize its potential as a commercial gas sensor, demand for a graphene-based device of low-limit detection, high sensitivity, and fast response time needs to be met. Here, we demonstrate a metal/insulator/semiconductor (MIS) based gas sensor consisting of as-grown epitaxial graphene nanowalls (EGNWs)/silicon carbide (SiC)/silicon (Si) structure. The unique edge dominant three-dimensional (3D) EGNWs based MIS device achieved an extraordinarily low limit of detection (0.5 ppm) and unprecedented sensitivity (82 μA/ppm/cm 2 for H 2 ) with a fast response of shorter than 500 ms. These unique properties of our MIS device are attributed to the abundance of vertically oriented nanographitic edges and structural defects that act as extra-favorable adsorption sites and exhibit fast electron-Transfer kinetics through the edges. Our experimental findings can pave the way for the realization of high-performance 3D graphene-based gas sensor devices. © 2019 American Chemical Society.
Subjects
3D graphene nanowalls; fast electron transfer; gas sensors; metal/insulator/semiconductor (MIS) heterostructure; nanographitic edges
Other Subjects
Carbides; Chemical sensors; Electron transitions; Gas detectors; Gases; Graphene devices; Intelligent systems; Silicon carbide; Epitaxial graphene; Fast electron transfer; Fast response time; Gas sensor devices; Limit of detection; nanographitic edges; Nanowalls; Threedimensional (3-d); Graphene
Type
journal article