posted on 2021-08-31, 14:12authored byAmir Zulkefli, Bablu Mukherjee, Ryoji Sahara, Ryoma Hayakawa, Takuya Iwasaki, Yutaka Wakayama, Shu Nakaharai
Using
a single-device two-dimensional (2D) rhenium disulfide (ReS2) field-effect transistor (FET) with enhanced gas species
selectivity by light illumination, we reported a selective and sensitive
detection of volatile organic compound (VOC) gases. 2D materials have
the advantage of a high surface-area-to-volume ratio for high sensitivity
to molecules attached to the surface and tunable carrier concentration
through field-effect control from the back-gate of the channel, while
keeping the top surface open to the air for chemical sensing. In addition
to these advantages, ReS2 has a direct band gap also in
multilayer cases, which sets it apart from other transition-metal
dichalcogenides (TMDCs). We take advantage of the effective response
of ReS2 to light illumination to improve the selectivity
and gas-sensing efficiency of a ReS2-FET device. We found
that light illumination modulates the drain current response in a
ReS2-FET to adsorbed molecules, and the sensing activity
differs depending on the gas species used, such as acetone, ethanol,
and methanol. Furthermore, wavelength and carrier density rely on
certain variations in light-modulated sensing behaviors for each chemical.
The device will distinguish the gas concentration in a mixture of
VOCs using the differences induced by light illumination, enhancing
the selectivity of the sensor device. Our results shed new light on
the sensing technologies for realizing a large-scale sensor network
in the Internet-of-Things era.