Self‐Formed Channel Devices Based on Vertically Grown 2D Materials with Large‐Surface‐Area and Their Potential for Chemical Sensor Applications

Abstract

2D layered materials with sensitive surfaces are promising materials for use in chemical sensing devices, owing to their extremely large surface-to-volume ratios. However, most chemical sensors based on 2D materials are used in the form of laterally defined active channels, in which the active area is limited to the actual device dimensions. Therefore, a novel approach for fabricating self-formed active-channel devices is proposed based on 2D semiconductor materials with very large surface areas, and their potential gas sensing ability is examined. First, the vertical growth phenomenon of SnS nanocrystals is investigated with large surface area via metal-assisted growth using prepatterned metal electrodes, and then self-formed active-channel devices are suggested without additional pattering through the selective synthesis of SnS nanosheets on prepatterned metal electrodes. The self-formed active-channel device exhibits extremely high response values (>2000% at 10 ppm) for NO along with excellent NO selectivity. Moreover, the NO gas response of the gas sensing device with vertically self-formed SnS nanosheets is more than two orders of magnitude higher than that of a similar exfoliated SnS -based device. These results indicate that the facile device fabrication method would be applicable to various systems in which surface area plays an important role.

Strategy and Future Prospects to Develop Room-Temperature-Recoverable NO2 Gas Sensor Based on Two-Dimensional Molybdenum Disulfide

“…The high activity of the edges boosts the motivation to grow edge-enriched film by forming the various morphology of MoS 2 nanoflakes such as vertical aligned MoS 2 , MoS 2 nanowires, MoS 2 spheres etc. Kim et al fabricated 2D SnS 2 and develop NO 2 sensor by enhancing the active sites [ 251 ]. The vertically aligned SnS 2 showed high NO 2 reactivity due to the presence of a large number of active sites in comparison to the basal plane SnS 2 .…”

“…Shim et al synthesized SiO 2 nanorods (NRs) and decorated them with MoS 2 flakes [ 252 ]. These SiO 2 NRs enhanced the catalytic activity of MoS 2 flakes by exposing more edges of MoS 2 flakes [ 251 ]. Hence, the NO 2 detection ability of SiO 2 NRs encapsulated with MoS 2 is increased.…”

Ultrafast and Stable Planar Photodetector Based on SnS2 Nanosheets/Perovskite Structure

“…In a viable development point of view, earth-abundant 2D materials are more crucial for prevalent use in the novel optoelectronic devices 1, 8,9 .. In this regard, the SnS2 crystal, belonging to IV-VIA group with electronic/optical band gap of about 2.1-2.31eV displays a proper candidate for using in nano-electronic/optoelectronic and photoelectron chemistry 10,11 .. Morover , achiveing vertical TMD structures could be the promising geometry in devices due to including more active surface area and highly active edge-sites of the layers rather than the basal planes 12 . To attain a vertical device, getting the growth of free-standing vertical nanosheets on the planer substrate is the major bottleneck, because,unlike the 1D semiconductor nanowires, generally, the preferable growth direction of the 2D crystals is parallel to the substrates 13,14 .…”

Growth characteristics of tin sulphides crystals by the vapour transport method using SnS and sulphur powders: effect of temperature and pressure

“…Moreover, tin sulphides have many interesting physical properties and are readily applicable to semiconductor‐based devices. SnS 2 exhibits n‐type semiconductor properties with a relatively large band gap of 2.18–2.77 eV [1, 3], which means that it could be used as an electronic device [4], photoelectric device [5, 6], or chemical sensor [7]. SnS exhibits p‐type semiconductor characteristics having high photo‐sensitivity and a high absorption coefficient, which could make it useful in photoelectric applications [8, 9].…”