Graphene oxide integrated silicon photonics for detection of vapour phase volatile organic compounds
AuthorsLeo Tsui, H. C.
Knights, Andrew P.
Halsall, Matthew P.
Crowe, Iain F.; email: firstname.lastname@example.org
MetadataShow full item record
AbstractAbstract: The optical response of a graphene oxide integrated silicon micro-ring resonator (GOMRR) to a range of vapour phase Volatile Organic Compounds (VOCs) is reported. The response of the GOMRR to all but one (hexane) of the VOCs tested is significantly higher than that of the uncoated (control) silicon MRR, for the same vapour flow rate. An iterative Finite Difference Eigenmode (FDE) simulation reveals that the sensitivity of the GO integrated device (in terms of RIU/nm) is enhanced by a factor of ~2, which is coupled with a lower limit of detection. Critically, the simulations reveal that the strength of the optical response is determined by molecular specific changes in the local refractive index probed by the evanescent field of the guided optical mode in the device. Analytical modelling of the experimental data, based on Hill-Langmuir adsorption characteristics, suggests that these changes in the local refractive index are determined by the degree of molecular cooperativity, which is enhanced for molecules with a polarity that is high, relative to their kinetic diameter. We believe this reflects a molecular dependent capillary condensation within the graphene oxide interlayers, which, when combined with highly sensitive optical detection, provides a potential route for discriminating between different vapour phase VOCs.
CitationScientific Reports, volume 10, issue 1, page 9592
PublisherNature Publishing Group UK
DescriptionFrom Springer Nature via Jisc Publications Router
History: received 2020-01-07, accepted 2020-05-17, registration 2020-05-20, pub-electronic 2020-06-12, online 2020-06-12, collection 2020-12
Publication status: Published