Electron
Transport and CO Sensing Characteristics of Fe(II) Porphyrin with
Single-Walled Carbon Nanotube Electrodes
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Abstract
Electron transport and carbon monoxide
(CO) sensitive characteristics of Fe(II) porphyrin (PP-Fe) with two
single-walled carbon nanotube electrodes (SWCNTs) were studied using
nonequilibrium Green’s function (NEGF) formalism combined first-principles
density functional theory (DFT). When PP-Fe is connected to SWCNT
electrodes in diagonal configuration, owing to the fact that the electron
passes through the Fe center, it shows higher CO sensitivity than
that in para connection mode. Meanwhile, the PP-Fe sensor with armchair
SWCNTs is more sensitive to CO than that in zigzag junction, since
the coupling interaction between central molecule and armchair SWCNT
electrodes is stronger. The PP-Fe sensor anchored on armchair SWCNTs
in diagonal configuration can reach a current on–off ratio
of 2.1 × 10<sup>4</sup> in response to the chemisorption of CO,
showing better CO sensitive characteristics than that with zigzag
SWCNTs and metallic electrodes. With the development of experimental
techniques, it is completely possible to fabricate this kind of CO
sensor by experimental means