Ultrathin SnSe₂ Flakes Grown by Chemical Vapor Deposition for High‐Performance Photodetectors

Abstract

High-quality ultrathin single-crystalline SnSe2 flakes are synthesized under atmospheric-pressure chemical vapor deposition for the first time. A high-performance photodetector based on the individual SnSe2 flake demonstrates a high photoresponsivity of 1.1 × 10(3) A W(-1), a high EQE of 2.61 × 10(5)%, and superb detectivity of 1.01 × 10(10) Jones, combined with fast rise and decay times of 14.5 and 8.1 ms, respectively.

Highly Anisotropic GeSe Nanosheets for Phototransistors with Ultrahigh Photoresponsivity

“…The hole mobility ( µ ) of the device can be calculated by $\mu =\frac{d{I}_{\mathrm{ds}}}{d{V}_{\mathrm{ds}}}\cdot \frac{L}{W{C}_{\mathrm{normali}}{V}_{\mathrm{ds}}}$, where W and L are the width and length of the device, and C i is the capacitance per unit area (11.6 nF cm −2 for 300 nm SiO 2 layer in these experiments). The calculated on/off ratio and µ are ≈10 3 and 0.8 cm 2 V −1 s −1 at room temperature with V ds = 1 V, which are comparable with those of reported MoS 2 ,41 SnSe 2 ,28 and SnS 2 25, 42 FETs recently. To further explore the charge transport mechanism, we employed the carrier injection models such as thermionic emission and tunneling 43, 44, 45.…”

Booming Development of Group IV–VI Semiconductors: Fresh Blood of 2D Family

“…Generally, the preparation methods can be classified into top‐down and bottom‐up methods, such as mechanical exfoliation,72, 92, 116 solvothermal method,97, 129, 140, 141 vapor deposition,69, 76, 118, 142 atomic layer deposition,126, 143 and so on. In the following context, we will focus on four methods.…”

“…Recently, Zhai and co‐workers76 adopted a newly Sn precursor (SnI 2 ) and achieved large area of SnSe 2 nanosheets with ultrathin thickness. They considered that SnI 2 takes some advantages over other solid precursors such as low melting point (≈320 °C), which may providing more uniform and stable growth conditions during CVD procedure for the growth of ultrathin SnSe 2 flakes.…”

“…Zhai and co‐workers76 fabricated a high performance photodetector based on few‐layer SnSe 2 flake with a high responsivity of 1.1 × 10 3 A W −1 , as well as a fast response time of 8.1 ms due to the high‐quality and ultrathin thickness. Furthermore, Zhai and co‐workers118 constructed high performance phototransistors based on ultrathin SnS 2 nanosheets with a high responsivity of 261 A W −1 and fast response time of 16 ms, they systematically studied the modulation of back‐gate voltage on the photodetection behaviors.…”

“…In view of the difficulty in large‐scale synthesis via mechanical exfoliation, Peng and co‐workers75 in 2015 demonstrated for the first time the controlled synthesis of thin SnS 2 nanosheets arrays by predefined metal seeds with the average thickness of 20 nm, thereby providing a new approach to the large‐scale production. Recently, Zhai and co‐workers76 first time achieved large area of ultrathin SnSe 2 nanosheets (≈1.5 nm, corresponding to two layers) by employing a newly Sn precursor (SnI 2 ), which further flourish the family of 2DLMCs. More importantly, 2D GIVMCs have demonstrated many interesting physical properties13, 77 and possible applications in electronics and photonics.…”