Tellurium nanoparticles are used for broadband solar energy harvesting and efficient photothermal conversion.

Through the excitation of plasmon resonance, the energy of plasmonic nanoparticles either reradiates through light scattering or decays into energetic electrons (absorption). The plasmon-induced absorption can greatly enhance the efficiency of solar energy harvesting, local heating, photodetection and photocatalysis. Here, we demonstrate that heavily self-doped titanium oxide nanoparticles (TiO1.67 analogue arising from oxygen vacancies in rutile TiO2) with the plasmon resonance dominated by an interband transition shows strong absorption to build a broadband perfect absorber in the wavelength range from 300 to 2000 nm covering the solar irradiation spectrum completely. The absorptivity of the fabricated array is greater than 90% in the whole spectral range. And the broadband and strong absorption is due to the plasmon hybridization and hot spot generation from near-touching TiO1.67 nanoparticles with different sizes. What is more, the local heating of a TiO1.67 nanoparticle layer is fast and effective. The temperature increases quickly from 30 °C to 80 °C within 200 seconds. This local heating can realize rapid solar-enabled evaporation which can find applications in large-scale distillation and seawater desalination. These findings actually open a pathway for applications of these newly developed plasmonic materials in the energy and environment fields.

Monolayer or few-layer molybdenum disulfide (MoS 2 ) with intriguing physical properties enables a wide range of applications such as photocatalysis and photodetection. The controllable light−matter interaction in MoS 2 nanoflakes with different numbers of layers is critical for developing new optoelectronic functionalities. Recently, plasmonic nanostructures have been used to obtain strong near-field enhancement for the effective photoluminescence (PL) manipulation of MoS 2 . However, it is still unclear whether the PL manipulation is dominated by electron injection processes or the strong field induced Purcell effect so far. Here, we investigate the PL manipulation of MoS 2 nanoflakes with different numbers of layers using Au nanoparticles with different aggregate states. Combining the measured PL and scattering spectra, the Kelvin probe force microscopy images at the single-particle level, and the numerical simulations, we figure out how the electron injection and strong field enhancement contribute to the PL manipulation and why PL quenching occurs in few-layer flakes but PL enhancement occurs in thicker flakes. These findings would give us a greater understanding of the interaction between two-dimensional materials and plasmonic nanostructures.

Strong Coulomb interactions in monolayer transition metal dichalcogenides (TMDs) produce strongly bound excitons, trions, and biexcitons. The existence of multiexcitonic states has drawn tremendous attention because of its promising applications in quantum information. Combining different monolayer TMDs into van der Waals (vdW) heterostructures opens up opportunities to engineer exciton devices and bring new phenomena. Spatially separated electrons and holes in different layers produce interlayer excitons. Although much progress has been made on excitons in single layers, how interlayer excitons contribute the photoluminescence emission and how to tailor the interlayer exciton emission have not been well understood. Here, room temperature strong coupling between interlayer excitons in the WS 2 /MoS 2 vdW heterostructure and cavity‐enhanced Mie resonances in individual silicon nanoparticles (Si NPs) are demonstrated. The heterostructures are inserted into a Si film‐Si NP all‐dielectric platform to realize effective energy exchanges and Rabi oscillations. Besides mode splitting in scattering, tunable interlayer excitonic emission is also observed. The results make it possible to design TMDs heterostructures with various excitonic states for future photonics devices.

The photoluminescence of WS2 flakes can be manipulated by an individual Si nanoparticle.