Covalent Modification of MoS₂ with Poly(N‐vinylcarbazole) for Solid‐State Broadband Optical Limiters

Abstract

New soluble MoS2 nanosheets covalently functionalized with poly(N-vinylcarbazole) (MoS2-PVK) were in situ synthesized for the first time. In contrast to MoS2 and MoS2 /PVK blends, both the solution of MoS2 -PVK in DMF and MoS2-PVK/poly(methyl methacrylate) (PMMA) film show superior nonlinear optical and optical limiting responses. The MoS2-PVK/PMMA film shows the largest nonlinear coefficients (βeff) of about 917 cm GW(-1) at λ=532 nm (cf. 100.69 cm GW(-1) for MoS2/PMMA and 125.12 cm GW(-1) for MoS2/PVK/PMMA) and about 461 cm GW(-1) at λ=1064 nm (cf. -48.92 cm GW(-1) for MoS2/PMMA and 147.56 cm GW(-1) for MoS2/PVK/PMMA). A larger optical limiting effect, with thresholds of about 0.3 GW cm(-2) at λ=532 nm and about 0.5 GW cm(-2) at λ=1064 nm, was also achieved from the MoS2-PVK/PMMA film. These values are among the highest reported for MoS2-based nonlinear optical materials. These results show that covalent functionalization of MoS2 with polymers is an effective way to improve nonlinear optical responses for efficient optical limiting devices.

Pyrolytically Modified Polyacrylonitrile‐Covalently Grafted MoS2 Nanosheets for a Nonvolatile Rewritable Memory Device

“…Like graphene and carbon nanotubes, the MoS 2 nanosheets are insoluble in any organic solvents, which makes them more difficulty to be fabricated into the thin film devices. To solve practical solution‐processability problems of the MoS 2 nanosheets, it would be an ideal and feasible way to design and synthesize MoS 2 ‐based solution‐processed organic/polymeric materials . However, synthesis of highly soluble MoS 2 nanosheets is still a challenge at the moment.…”

Facile synthesis of two-dimensional WS2 with reverse saturable absorption and nonlinear refraction properties in the PMMA matrix

“…Due to the energy band gap of TMDs changing from the indirect to direct band as reducing the number of layers, a series of exotic photonic properties emerge in few-layer TMDs, which cannot be observed in the bulk TMDs. Several research groups demonstrated strong OL performances in few-layer TMDs and few-layer TMDs-composites for ps or ns laser pulse [6,20]. The fs OL effect with very low threshold of WS 2 (or other TMDs) solid material has not yet been reported so far.…”

Facile synthesis route for MoS2-polyvinylpyrrolidone aerogels

“…Its unique structure leads to exotic electronic properties and tunable bandgaps (1.2-1.9 eV) [12] for promising applications in biological imaging [13] and optical limiter [14]. Due to the explosive studies on 3D aerogels, there is a growing demand for MoS 2 aerogels to achieve their potential applications.…”