Mastering VOC detection for better indoor air quality
2014 (English)Conference paper, Abstract (Refereed)
In this study, we use two different sensor technologies based on gas sensitive silicon carbide field effect transistors (SiC-FETs) and epitaxial graphene on SiC (EG/SiC) for highly sensitive and selective detection of trace amounts of three hazardous volatile organic compounds (VOCs), i.e. formaldehyde (CH2O), benzene (C6H6), and naphthalene (C10H8), present in indoor environments in concentrations of health concern.
Iridium and platinum are used as sensing layers for the gate contacts. The FET sensors are operated at high temperature, under static and dynamic conditions. Excellent detection limits of 10 ppb for CH2O, about 1 ppb for C6H6, and below 0.5 ppb for C10H8 are measured at 60 % relative humidity (r.h.) . The selectivity of the sensors is increased by temperature cycled operation and data evaluation based on multivariate statistics. Discrimination of CH2O, C6H6, and C10H8 independent of the level of background humidity is possible with a very high cross-validation rate up to 90 % . These results are very encouraging for indoor air quality control, being below the threshold limits recommended by the WHO guidelines.
Graphene-based chemical sensors offer the advantage of extreme sensitivity due to graphene’s unique electronic properties and the fact that every single atom is at the surface and available to interact with gas molecules. For this reason, uniform monolayer graphene is crucial , which is guaranteed by our optimized epitaxial growth process. Graphene-based chemical gas sensors normally show ultra-high sensitivity to certain gas molecules but suffer from poor selectivity. Functionalization or modification of the graphene surface can improve selectivity, but most such measures result in poor reproducibility. We demonstrate reproducible, non-destructive means of graphene surface decoration with nanostructured metals and metal oxides, and study their effect on the gas interactions at the graphene surface.
Place, publisher, year, edition, pages
www.eunetair.it , 2014.
chemical sensors, silicon carbide, graphene, field effect transistor, volatile organic compounds
Other Physics Topics
IdentifiersURN: urn:nbn:se:liu:diva-115565OAI: oai:DiVA.org:liu-115565DiVA: diva2:795548
3rd Scientific Meeting of COST Action TD1105 EuNetAir, December 3-5, 2014, Istanbul, Turkey
FunderEU, FP7, Seventh Framework Programme, 604311