Liquid‐Metal Synthesized Ultrathin SnS Layers for High‐Performance Broadband Photodetectors

Abstract

Atomically thin materials face an ongoing challenge of scalability, hampering practical deployment despite their fascinating properties. Tin monosulfide (SnS), a low‐cost, naturally abundant layered material with a tunable bandgap, displays properties of superior carrier mobility and large absorption coefficient at atomic thicknesses, making it attractive for electronics and optoelectronics. However, the lack of successful synthesis techniques to prepare large‐area and stoichiometric atomically thin SnS layers (mainly due to the strong interlayer interactions) has prevented exploration of these properties for versatile applications. Here, SnS layers are printed with thicknesses varying from a single unit cell (0.8 nm) to multiple stacked unit cells (≈1.8 nm) synthesized from metallic liquid tin, with lateral dimensions on the millimeter scale. It is reveal that these large‐area SnS layers exhibit a broadband spectral response ranging from deep‐ultraviolet (UV) to near‐infrared (NIR) wavelengths (i.e., 280–850 nm) with fast photodetection capabilities. For single‐unit‐cell‐thick layered SnS, the photodetectors show upto three orders of magnitude higher responsivity (927 A W−1) than commercial photodetectors at a room‐temperature operating wavelength of 660 nm. This study opens a new pathway to synthesize reproduceable nanosheets of large lateral sizes for broadband, high‐performance photodetectors. It also provides important technological implications for scalable applications in integrated optoelectronic circuits, sensing, and biomedical imaging.

Recent Advances in 2D Materials for Photodetectors

“…Krishnamurthi et al. [ 52 ] synthesized SnS ultrathin (single unit cell: 0.8 nm; stacked unit cell: 1.5 nm) film with millimeter‐sized by using unique transferring metallic liquid tin method, and demonstrated a high photoresponsivity (927 A W −1 ), broadband response (280–850 nm), and fast response time (millisecond level) photodetector. Especially, Yu et al.…”

State-of-the-art surface oxide semiconductors of liquid metals: an emerging platform for development of multifunctional two-dimensional materials

“…A broadband photodetector was developed based on monolayer, bilayer and few-layer SnS crystalline 2D lms with 0.8 nm to 1.8 nm thickness. 258 The 2D lms were initially delaminated from liquid tin and then transformed into SnS lms via reaction with H 2 S gas. The synthesized 2D SnS lms exhibited broadband spectral response ranging from deep-ultraviolet (UV) to near-infrared (NIR) wavelengths.…”

“…A photodetector based on a single-unit-cell-thick SnS lm showed a photoresponsivity of 927 A W À1 at an illumination wavelength of 660 nm which was three orders of magnitude higher than the photoresponsivity of commercial photodetectors under the same operating conditions. 258 4.1.11 Bi 2 S 3 phototransistor. The large-area developed 2D Bi 2 S 3 crystalline nanosheets were extracted using a liquid-metal based synthesis approach.…”

SnSe Nanosheets: From Facile Synthesis to Applications in Broadband Photodetections

“…In recent years, various efforts have been developed for fabricating 2D NSs, such as one-pot synthetic method [ 12 ], microwave hydrothermal technique [ 13 ], Li-intercalation exfoliation [ 14 ], ultrasonic liquid exfoliation [ 15 , 16 ], liquid metal synthesis [ 17 , 18 ]. SnSe, a member of layered IV–VI chalcogenides materials, is a promising candidate for photodetectors and solar cells due to the low cost, low toxicity, stability, a high coefficient of light absorption [ 19 , 20 , 21 , 22 , 23 , 24 ].…”