| dc.description.abstract |
In this paper, we have explored Parylene-C
(PC) as a sensing material for its unique signatures and
selectivity for explosive sensing. We have used a bilayer
deposition process to fabricate bottom-gate-topcontact
(BGTC) OFET structures. Opening of dangling
bonds on subjecting PC to plasma oxidation (POPC)
renders these molecules to be employed as a receptor
material in sensing vapors of both explosives and nonexplosives
such as Trinitrotoulene (TNT), 1,3,5 trinitro-
1,3,5-triazacyclohexane(RDX), PETN, Dinitrobenzene
(DNB), Nitrobenzene (NB), Benzoquinone (BQ) and
Benzophenone (BP). The change in (a) the vibration
modes of the molecule by infrared spectroscopy (FTIR)
(b) surface potential of POPC by Kelvin Probe Force
Microscopy (KPFM) and (c) electrical characterization
by IV measurements of PC based OFET on exposing to
vapors have been systematically studied. Different
signatures for all the analytes have been observed while
exact and perfect selectivity for TNT, RDX were found
from I-V studies and for PETN by KPFM studies. Thus,
the OFET device based chemical sensors demonstrated
here with improved sensitivity and excellent selectivity,
stand as promising candidates for explosives detection. |
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