WSe₂ crystals on paper: flexible, large area and broadband photodetectors

Abstract

The paper-based photodetector has recently captivated a great deal of attention in various optoelectronics applications because of facile, cost effective and green synthesis. Two-dimensional transition metal dichalcogenides materials are promising for photodetection under the broad spectral range. In this work, we have fabricated paper-based device by rubbing the tungsten diselenide (WSe 2 ) crystals on paper substrate. Low-cost, facile and green synthesis technique was employed to make a high-performance paper-based WSe 2 photodetector. Paper-based photodetector was fabricated via non-toxic simply rubbing process of WSe 2 nanosheets on lowcost bio-degradable paper. The photodetector shows good responsivity of 72.5 μA W −1 and detectivity at around 2.4×10 7 Jones at very low bias (1.0 V) at wavelength of 780 nm, respectively. Due to good photo-absorption strength, photodetector exhibits excellent photoresponse over wide wavelength range from visible to near infrared. This device also shows very good flexibility with a stable photo-response. This device shows a general and reliable study for the design of photodetectors that is eco-friendly and cost-effective. Overall studied results of the fabricated device indicate that they have the ability to be used in large-scale preparation of the device.

Solvent-free fabrication of broadband WS₂ photodetectors on paper

“…At a bias voltage of 5 V, the WS 2 device with Au electrodes delivers a significantly enhanced responsivity of 193.9 mA W −1 under the same power intensity (35 mW cm −2 ) compared with the WS 2 device with graphite electrodes (6.4 mA W −1 ). These responsivity val-ues measured are superior to that of other TMDCs-based photodetectors (0.018−124 mA W −1 ) fabricated by solvent-involved approaches 37,56,58−60 , and that of the WS 2 photodetectors with atomically thin layers (5×10 −3 −12.5 mA W −1 ) obtained through CVD 61−63 , magnetron sputtering 64,65 , and mechanical exfoliation methods 66 . Table 1 compares their typical device characteristics in further detail.…”

Solution Processed Photodetectors with PVK-WS2 Nanotube/Nanofullerene Organic–Inorganic Hybrid Films

“…Photodetectors are the core functional optoelectronic devices and have broad application prospects in many areas such as optical communications, video imaging, and medical detection. , By constructing different device structures, self-powered photodetectors can be realized, which is of great significance for wide applications. − Two-dimensional (2D) layered materials, represented by graphene , transition-metal dichalcogenides (TMDCs) , and oxides, have attracted significant attention due to their unique electronic and optical properties. − Especially, tungsten disulfide (WS 2 ) with an X–metal–X structure is a typical representative; − it has a structure similar to those of the other dichalcogenides belonging to the P 6 3 / mmc space group. The physical properties of WS 2 could be strongly affected by edge structures and atomic defects. − Among them, one-dimensional (1D) WS 2 nanotubes (WS 2 -NTs) and zero-dimensional (0D) WS 2 nanofullerenes (WS 2 -FLs) are very interesting materials with unique properties; their mechanical and electrochemical properties have been studied in previous years .…”

Enhanced Photoresponse and Wavelength Selectivity by SILAR-Coated Quantum Dots on Two-Dimensional WSe2 Crystals

“…The WSe 2 flakes have unique properties such as high carrier mobility (250 cm 2 /V s), strong optical absorption (2.13 cm –1 ), large luminescence intensity, and high photoconversion efficiency that make them a potent choice among 2D materials for electronic and optoelectronic applications. WSe 2 has a band gap in the range of ∼1.3 eV (as bulk form) to ∼1.8 eV (monolayer) that causes excellent absorption to the visible and near-infrared (NIR) regions, rather than the UV region . Stronger optical absorption can be achieved by fabricating heterostructures using TMDs and active semiconducting materials with designed energy band gap matching in which the responsivity can be enhanced by injecting more photocarriers and less recombination. , …”

“…WSe 2 has a band gap in the range of ∼1.3 eV (as bulk form) to ∼1.8 eV (monolayer) that causes excellent absorption to the visible and near-infrared (NIR) regions, rather than the UV region. 14 Stronger optical absorption can be achieved by fabricating heterostructures using TMDs and active semiconducting materials with designed energy band gap matching in which the responsivity can be enhanced by injecting more photocarriers and less recombination. 15,16 It is known that most quantum dots as artificial atoms have tunable band gaps, strong optical absorption to a broad range of wavelengths from UV to IR, and high quantum efficiencies that make them interesting materials for heterostructure photodetectors.…”