Large‐Scale Growth and Field‐Effect Transistors Electrical Engineering of Atomic‐Layer SnS₂

Abstract

2D layers of metal dichalcogenides are of considerable interest for high‐performance electronic devices for their unique electronic properties and atomically thin geometry. 2D SnS2 nanosheets with a bandgap of ≈2.6 eV have been attracting intensive attention as one potential candidate for modern electrocatalysis, electronic, and/or optoelectronic fields. However, the controllable growth of large‐size and high‐quality SnS2 atomic layers still remains a challenge. Herein, a salt‐assisted chemical vapor deposition method is provided to synthesize atomic‐layer SnS2 with a large crystal size up to 410 µm and good uniformity. Particularly, the as‐fabricated SnS2 nanosheet‐based field‐effect transistors (FETs) show high mobility (2.58 cm2 V−1 s−1) and high on/off ratio (≈108), which is superior to other reported SnS2‐based FETs. Additionally, the effects of temperature on the electrical properties are systematically investigated. It is shown that the scattering mechanism transforms from charged impurities scattering to electron–phonon scattering with the temperature. Moreover, SnS2 can serve as an ideal material for energy storage and catalyst support. The high performance together with controllable growth of SnS2 endow it with great potential for future applications in electrocatalysis, electronics, and optoelectronics.

Giant‐Enhanced SnS2 Photodetectors with Broadband Response through Oxygen Plasma Treatment

“…Convincingly, a single Raman peak at 314 cm −1 , which represents A g 1 is observed for both the original and the O 2 ‐plasma‐treated SnS 2 flake and was similar to those previously reported. [ 2,22 ] The XRD pattern of SnS 2 can be attributed to the hexagonal structure (JCPDS PDF number 23–0677). Therefore, the results exhibit a single crystal SnS 2 with c‐ axis preferential orientation (Figure S1, Supporting Information).…”

“…[ 21 ] In an ambient condition, the extracted carrier mobility from the treated SnS 2 FET is one of the highest reported so far. [ 1,22 ] Figure 3b shows the distinctive gating response of the original and the O 2 ‐plasma‐treated SnS 2 FET between −40 and 40 V at V ds = 1 V, they both exhibit n‐type channel behavior and the threshold voltage decreases after the plasma treatment which indicates faster response. Furthermore, Figure 3c shows typical I ds – V ds curves of the device under dark with improved dark currents after plasma treatment.…”

“…[ 4,5,14 ] In comparison with the famous transition metal dichalcogenides (MoS 2 , WS 2 ), [ 15–19 ] SnS 2 ‐based photodetector has been reported to demonstrate photoresponsivity as high as 261 A W −1 , [ 20 ] and 230 cm 2 V −1 s −1 carrier mobility for solution‐gated field‐effect transistors (FETs), [ 21 ] hence making it a promising candidate in electronic and optoelectronic applications. [ 22 ]…”

Controlling Atomic Layer Deposition of 2D Semiconductor SnS2 by the Choice of Substrate

“…[ 12,13 ] It crystallizes in the CdI 2 ‐type 2D structure (1T phase) similar to many TMDCs [ 12,14 ] and has a fairly large, indirect band gap of approximately 2.2 eV in bulk [ 13,15 ] and 2.4−2.6 eV as a monolayer. [ 15,16 ] SnS 2 has already shown performance comparable to the benchmark 2D semiconductor, MoS 2 , in applications such as FETs [ 9,12,17–19 ] and photodetectors. [ 12,20 ] Furthermore, possible reduction in short‐channel leakage [ 20,21 ] due to the larger, indirect band‐gap of SnS 2 and higher predicted mobility [ 22 ] compared to MoS 2 make SnS 2 a favorable material for electronics.…”

“…Thus far, CVD has been mostly used to produce high‐quality, isolated few‐layer flakes of SnS 2 at 450–700 °C. [ 16,18,32,33 ] CVD of continuous SnS 2 films was demonstrated recently, but films below 3–4 nm in thickness remained discontinuous and even 15 nm thick films contained some holes. [ 34,35 ] ALD has been used to deposit continuous SnS 2 films with thicknesses from approximately two up to tens of monolayers.…”