Large‐Size Growth of Ultrathin SnS₂ Nanosheets and High Performance for Phototransistors

Abstract

2D SnS2 nanosheets have been attracting intensive attention as one potential candidate for the modern electronic and/or optoelectronic fields. However, the controllable large‐size growth of ultrathin SnS2 nanosheets still remains a great challenge and the photodetectors based on SnS2 nanosheets suffer from low responsivity, thus hindering their further applications so far. Herein, an improved chemical vapor deposition route is provided to synthesize large‐size SnS2 nanosheets, the side length of which can surpass 150 μm. Then, ultrathin SnS2 nanosheet‐based phototransistors are fabricated, which achieve high photoresponsivities up to 261 A W−1 (with a fast rising time of 20 ms and a falling time of 16 ms) in air and 722 A W−1 in vacuum, respectively. Furthermore, the effects of back‐gate voltage and air adsorbates on the optoelectronic properties of the SnS2 nanosheet have been systematically investigated. In addition, a high‐performance flexible photodetector based on SnS2 nanosheet is also fabricated with a high responsivity of 34.6 A W−1.

Ultrathin 2D GeSe2 Rhombic Flakes with High Anisotropy Realized by Van der Waals Epitaxy

“…For CVD methods, one of the key challenges is how to control the flux of the metal and chalcogen/selenium precursors as it is delivered to the substrates. [29,30] The substrate is another key element in determining the nucleation and growth of material from the vapor sources. [28] As a result, the halide, GeI 4 , which has a low melting point of ≈146 °C, was employed as the metal precursor; its melting point is close to that of Se (≈221 °C), allowing for the formation of a steady vapor flux.…”

Flexible Photodetectors Based on Novel Functional Materials

“…2D metal chalcogenides such as GaS, GaSe, GaTe, InSe, SnS 2 , Bi 2 S 3 , and In 2 Se 3 , have also attracted a great deal of interest for flexible photodetection for their appealing optical and optoelectrical properties, and excellent mechanical flexibility. These 2D nanosheets with high‐crystallinity are usually prepared via mechanical exfoliation or other methods and then transferred onto flexible substrates, or can be directly grown on flexible mica substrates following a van der Waals epitaxial growth mechanism, with an aim to construct flexible photodetectors. The flexible devices exhibit extraordinary photoresponse characteristics with responsivities ranging from tens of mA W −1 to thousands of A W −1 , and rapid response speeds faster than tens of milliseconds, as well as outstanding mechanical stability upon deformation.…”

Recent advances in low‐dimensional semiconductor nanomaterials and their applications in high‐performance photodetectors

“…F, Current‐time curves of flexible SnS 2 PDs before and after bending 200 times. Reproduced with permission . Copyright 2016, Wiley‐VCH…”

“…For example, B‐P is a widely studied material in high‐performance flexible electronic devices . Since the first B‐P FETs were successfully fabricated on PI substrates (Figure A), B‐P research in flexible electronics has been ongoing.…”

“…SnS 2 flexible PDs based on PET substrates show potential in the field of flexible electronics. The measurement results show that the SnS 2 flexible PDs have a high response rate of 34.6 A W −1 , and the bending test also proves its good mechanical stability (Figure E,F) …”