Tungsten diselenide – WSe2, a 2D material – is a transition metal dichalcogenide (TMDC), with the ability to convert light to electricity and vice versa. This suggests that it and other TMDCs could be suitable for use in such devices as thin film solar cells, photodetectors, flexible logic circuits and sensors. However, because WSe2 is a single layer, its absorption and photoluminescence properties are reduced and its potential applications limited.
By incorporating monolayers of tungsten diselenide onto gold substrates with nanosized trenches, the team, led by Professor Andrew Wee, enhanced the nanomaterial’s photoluminescence by up to 20,000 times.
Prof Wee said: “The key to this work is the design of the gold plasmonic nanoarray templates. In our system, the resonances can be tuned to be matched with the pump laser wavelength by varying the pitch of the structures. This is critical for plasmon coupling with light to achieve optimal field confinement.”
The team now plans to investigate the effectiveness of the lateral gold plasmon in enhancing the second harmonic generation and electroluminescence of TMDCs. They will also investigate these effects in other 2D transition metal dichalcogenides with different band gaps.
