Emerging photoluminescence from defective vanadium diselenide nanosheets

In this paper, for the first time to our knowledge in the literature, we demonstrate photoluminescence from two-dimensional (2D) vanadium diselenide (VSe2) nanosheets (NSs). The preparation of these nanostructures is carried out with a combinational method based on nanosecond pulsed laser ablation (PLA) and chemical exfoliation. For this aim, VSe2 bulk is first ablated into nanoparticles (NPs) inside a water solution. Afterward, NPs are chemically exfoliated into NSs using lithium intercalation via ultrasonic treatment. Although VSe2 is a semimetal in its bulk form, its nanostructures show photo-responsive behavior, and it turns into a strongly luminescent material when it is separated into NSs. Based on the obtained results, the surface defects induced during the PLA process are the origin of this photoluminescence from NSs. Our findings illustrate that this new material can be a promising semiconductor for photovoltaic and light emitting diode applications. (c) 2018 Chinese Laser Press