Tungsten-disulphide-based heterojunction photodetector
Document Type
Article
Publication Date
1-1-2019
Abstract
Two-dimensional (2D) materials have realized significant new applications in photonics, electronics, and optoelectronics. Among these materials is tungsten disulphide (WS2), which is a 2D material that shows excellent optoelectronic properties, tunable/sizable bandgap in the visible range, and good absorption. A polycrystalline WS2 thin film is successfully deposited on a substrate using radio frequency magnetron sputtering at room temperature. The x-ray diffraction pattern reveals two hexagonal structured peaks along the (100) and (110) planes. Energy-dispersive x-ray spectroscopy reveals a non-stoichiometric WS2 film with 1.25 ratio of S/W for a 156.3 nm thick film, while Raman shifts are observed at the E1 2g and A1g phonon modes located at 350.70 cm−1 and 415.60 cm−1, respectively. A sandwiched heterojunction photodetector device is successfully fabricated and illuminated within the violet range at 441 nm and 10 V of bias voltage. The maximum photocurrent values are calculated as 0.95 μA, while the responsivity is observed at 169.3 mA W−1 and detectivity 1.48 × 108 Jones at illuminated power of 0.6124 μm. These results highlight the adaptability of the present technique for large-scale applications as well as the flexibility to promote development of advanced optoelectronic devices. © 2019 Optical Society of America.
Keywords
Energy dispersive spectroscopy, Heterojunctions, Magnetron sputtering, Optoelectronic devices, Photodetectors, Photons, Sulfur compounds, Thick films, Thin films
Divisions
photonics
Publication Title
Applied Optics
Volume
58
Issue
15
Publisher
Optical Society of America