Abstract
In this work, a low-cost resistive gas sensor based on graphene grown by CVD was fabricated and its sensitivity was studied in terms of defect density. CVD graphene was transferred using Polyurethane as sacrifice layer with low contamination and defect-free results. An atmospheric plasma etching system was used to homogeneously induce defects on the sensor’s active area, as investigated through Raman spectroscopy. Device sensing properties were significantly enhanced for greater defect density for both NH3 and NO2. The modified sensors were submitted to different concentrations of both target gas to assess detection limits and overall behavior. It was revealed that defective CVD graphene devices possess sensitivity up to ppm range with linear dependence in the range of values measured. The fabricated sensors presented little to no signal degradation after months of atmospheric exposure.
Highlights
Since graphene first gas detection investigation published in 2007 [1], numerous efforts have been made towards its extended application in the area [2, 3]. 2D materials, such as graphite, have attracted enormous attention given that they usually show different properties from their threedimensional counterparts
Since most chemical sensors are based in the interaction between an active surface and a target gas, it is straightforward to understand that graphene’s extremely high surface area/volume ratio makes it ideal for its use in gas sensing devices
A typical example of this is seen in graphene oxide films: as deposited, they present an enormous amount of adsorption sites given by its sheet irregular agglomeration, which causes high resistance values and poor effective contact [8]
Summary
Since graphene first gas detection investigation published in 2007 [1], numerous efforts have been made towards its extended application in the area [2, 3]. 2D materials, such as graphite, have attracted enormous attention given that they usually show different properties from their threedimensional counterparts. Since most chemical sensors are based in the interaction between an active surface and a target gas, it is straightforward to understand that graphene’s extremely high surface area/volume ratio makes it ideal for its use in gas sensing devices In this regard, the need to growth and isolate largearea graphene on suitable substrates for electronic applications becomes apparent. Numerous ab initio studies have found that defects on graphene enhance its sensing properties (DFTs) and experimental works have confirmed this behavior [9,10,11] It has been shown in the work by Salehi-Khojin et al [9] that defective graphene is more sensitive than pristine and that a combination of different types of defects is desired. The as-fabricated defective sensors present linear response variation with concentration for both gases, with detection limits ranging to the few ppm scale
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
