Two-dimensional bismuth nanosheets as prospective photo-detector with tunable optoelectronic performance

Abstract

Two dimensional Bi nanosheets have been employed to fabricate electrodes for broadband photo-detection. A series of characterization techniques including scanning electron microscopy and high-resolution transmission electron microscopy have verified that Bi nanosheets with intact lamellar structure have been obtained after facile liquid phase exfoliation. In the meanwhile, UV-vis and Raman spectra are also carried out and the inherent optical and physical properties of Bi nanosheets are confirmed. Inherited from the topological characteristics of Bi bulk counterpart, the resultant Bi nanosheet-based photo-detector exhibits preferable photo-response activity as well as environmental robustness. We then evaluate the photo-electrochemical (PEC) performance of the photodetector in 1 M NaOH and 0.5 M NaSO electrolytes, and demonstrated that the as-prepared Bi nanosheets may possess a great potential as PEC-type photo-detector. Additional PEC measurements show that the current density of Bi nanosheets can reach up to 830 nA cm, while an enhanced responsivity (1.8 μA W) had been achieved. We anticipate that this contribution can provide feasibility towards the construction of high-performance elemental Bi nanosheets-based optoelectronic devices in the future.

Centimeter‐scale growth of two‐dimensional layered high‐mobility bismuth films by pulsed laser deposition

“…As 15‐nm‐thick sample should be categorized as a bulk, the ultra‐small band gap of 0.075 eV is reasonable owing to its semimetal property. The change trend is also consistent with the previous theoretical and experimental results, which can be explained by quantum confinement effect . The narrow band gaps (0.075‐0.2 eV) of Bi thin films make them attractive as suitable candidates for optoelectronic devices in the mid‐infrared and far‐infrared regions.…”

“…The change trend is also consistent with the previous theoretical and experimental results, which can be explained by quantum confinement effect. 45,46 The narrow band gaps (0.075-0.2 eV) of Bi thin films make them attractive as suitable candidates for optoelectronic devices in the mid-infrared and far-infrared regions.…”

Self‐Powered Photodetectors Based on 2D Materials

“…At the same time, it exhibits a significant self‐powered photoresponse current at zero bias, which indicates that the device is a potential self‐powered photodetector. In another work, the 2D topological insulator Bi nanosheet has been successfully prepared by ultrasonic processing and applied to PEC‐type photodetectors . In the 1 m NaOH electrolyte, the PEC‐type photodetectors based on Bi nanosheets exhibited a preferred photoresponsive activity under light irradiation, which had a photocurrent density of 830 nA cm −2 and a light responsivity of 1.8 µA W −1 .…”

Structure dependent optoelectronic properties of monolayer antimonene, bismuthene and their binary compound

“…46 Promising indications of antimonene's broadband use as a photodetector or optical modulator have been shown recently. 47,48 Bismuthene's optical properties have not been vastly investigated yet, with only a few recent examples of electric field applications or its potential as a photonic-based device, 45,[49][50][51] hence the light-matter interaction within 2D bismuthene remains an area of interest. While the dynamical stability, electronic structure and topological features of SL BiSb binary compounds have been studied actively, 34,35,[52][53][54][55][56] very little is known about their optical properties.…”