Vapor–Liquid–Solid Growth of One-Dimensional Tin Sulfide (SnS) Nanostructures with Promising Field Emission Behavior

Abstract

Single-crystalline ultralong tin sulfide (SnS) nanowires has been grown by a thermal evaporation technique under optimized conditions on gold-coated silicon substrates, and for the first time, field emission investigations on the SnS nanowires at the base pressure of 1 × 10(-8) mbar are reported. It has been revealed that the surface morphology of the as-synthesized SnS nanostructures is significantly influenced by the deposition temperature and duration. Structural and morphological analyses of as-synthesized SnS nanostructures have been carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). To understand the optical and electronic properties of as-synthesized SnS nanowires, ultraviolet-visible (UV-vis), photoluminescence (PL), and X-ray photoelectron spectroscopy (XPS) studies were carried out. The SEM and TEM measurements reveal the formation of ultralong SnS nanowires, with an average diameter of 80 nm. A plausible explanation on the vapor-solid-liquid (VLS) growth mechanism based on the experimental results and reported literature has been presented. Furthermore, the field emission characteristics of the SnS nanowires are found to be superior to the other metal chalcogenide nanostructures. The synthesized SnS nanowire emitter delivers a high current density of ∼2.5 mA/cm(2) at an applied electric field of ∼4.55 V/μm. The emission current stability over a period of 6 h is observed to be good. The observed results demonstrate the potential of the SnS nanowire emitter as an electron source for practical applications in vacuum nano/microelectronic devices.

Structural characterization of SnS crystals formed by chemical vapour deposition

“…Several groups have previously used TEM to identify the crystal structure of SnS nanoparticles (Lu et al, 2015;Tarkas et al, 2017), nanosheets (Hori et al, 2014;Brent et al, 2015;Yang et al, 2015;Chao et al, 2016), nanorods (Suryawanshi et al, 2014;Chauhan et al, 2015) and micron-sized flakes (Xia et al, 2016;Tian et al, 2017) which were synthesised through various techniques. The TEM characterisation of the SnS nanosheets and flakes have been generally limited to plane view analysis and basic d-spacing measurements in cross section in order to confirm the phase of the material.…”

Electronic structures of SnS and SnS2

“…As anode material for Li‐ion batteries, SnS exhibits a lower irreversible capacity loss at the first cycle than SnS 2 and interesting performances . Other applications of SnS concern photocatalytic and photoelectrochemical properties , hydrogen storage , supercapacitors , electronic devices and thermoelectricity .…”

Facile solution synthesis of tin sulfide nanobelts for lithium-ion batteries

“…Amongst such materials, SnS possesses an orthorhombic structure, where tightly bound Sn-S atoms are connected by the van der Waals forces [10,11]. The crystallographic feature can facilitate Li + diffusion, and functions as the buffering layer to compensate for large volume changes [12].…”

“…Moreover, SnS is low-cost, nontoxic, abundant and heavy metal-free [11]. With its high specific capacity, low cost, nontoxicity, and high electrical conductivity, SnS is a promising material for various applications, such as in LIBs, field-emission applications, photodetector devices, photocatalysts, and optoelectronics [11,[13][14][15][16][17][18][19][20][21]. SnS with various nanostructures have been successfully synthesized through different methods [11][12][13][14][15][16][17][18][19][22][23][24].…”

“…With its high specific capacity, low cost, nontoxicity, and high electrical conductivity, SnS is a promising material for various applications, such as in LIBs, field-emission applications, photodetector devices, photocatalysts, and optoelectronics [11,[13][14][15][16][17][18][19][20][21]. SnS with various nanostructures have been successfully synthesized through different methods [11][12][13][14][15][16][17][18][19][22][23][24]. Nevertheless, the following issues are still inevitable: 1) synthesis is complicated and mostly requires the use of hexamethyldisilazane and annealing treatment under high temperature in N 2 gas; [5,12]; 2) limited control of SnS phase and morphology [11,14,18,23]; 3) andpoor electrochemical properties due toexcessive volume expansion during cycling [25].…”