Enhanced NO₂ Sensitivity in Schottky-Contacted n-Type SnS₂ Gas Sensors

Abstract

Layered materials are highly attractive in gas sensor research due to their extraordinary electronic and physicochemical properties. The development of cheaper and faster room-temperature detectors with high sensitivities especially in the parts per billion level is the main challenge in this rapidly developing field.Here, we show that sensitivity to NO 2 (S) can be greatly improved by at least two orders of magnitude using an n-type electrode metal. Unconventionally for such devices, the ln(S) follows the classic Langmuir isotherm model rather than S as is for a p-type electrode metal. Excellent device sensitivities, as high as 13,000% for 9 ppm and 97% for 1 ppb NO 2 , are achieved with Mn electrodes at room temperature, which can be further tuned and enhanced with the application of a bias. Long-term stability, fast recovery, and strong selectivity toward NO 2 are also demonstrated. Such impressive features provide a real solution for designing a practical high-performance layered material-based gas sensor.

Selectivity in trace gas sensing: recent developments, challenges, and future perspectives

“…Various gas sensing devices can be made of 2D materials, 6,102,255,271 e.g. , chemiresistors, 272,273 field-effect transistors (FETs), 274–278 layered semiconductor heterojunction, 279–281 surface acoustic wave (SAW) sensors, 282,283 conductometric semiconducting gas sensors, 284 impedance sensors. 285 Several theoretical studies show that 2D material-based gas sensors can achieve a detection limit of ppb levels and inclusion of cleansing system by using UV light, the detection limit can reach up to ppt level.…”

Strategies for Improving the Sensing Performance of Semiconductor Gas Sensors for High-Performance Formaldehyde Detection: A Review

“…With the exploration of the use of 2D material graphene in the field of gas sensing, exploring other new 2D crystal materials has been at the forefront of nanomaterials research. Apart from graphene, new 2D materials such as SnS2 [88], WS2 [89], MoSe2 [90],…”

“…With the exploration of the use of 2D material graphene in the field of gas sensing, exploring other new 2D crystal materials has been at the forefront of nanomaterials research. Apart from graphene, new 2D materials such as SnS 2 [88], WS 2 [89], MoSe 2 [90], MoS 2 [91], SnSe 2 [92] and black phosphorus [93] have been explored in depth due to their excellent capability in nano-electronic devices.…”

Gate-controlled gas sensor utilizing 1D–2D hybrid nanowires network

“…Two-dimensional (2D) semiconductors have attracted significant interest for active sensing materials. Their ultrathin thickness contributes a high specific surface area and a large number of reactive sites for charge transfer between gas molecules and the sensing material ( Dey, 2018 ; Donarelli and Ottaviano, 2018 ; McAlpine et al., 2007 ; Shalev, 2017 ; Yan et al., 2020 ). Based on these structural features, low operating temperature (near room temperature) has been reported for sensors based on 2D materials, especially transition metal dichalcogenides (TMDs), such as MoS 2 , WSe 2 , and SnSe 2 ( Cho et al., 2015 , 2016 ; Choi et al., 2017 ; Cui et al., 2020 ; Dey, 2018 ; Kang et al., 2019 ; Moumen et al., 2021 ; Ricciardella et al., 2017 ; Liu et al., 2021 ).…”