Enabling Persistent Luminescence of Eu in Nanoparticles through Interfacial Energy Transfer for Advanced X-ray Imaging.

Persistent luminescence (PersL) emerged recently in nanoparticles which greatly promotes and expands their frontier applications. However, achieving X-ray-activated PersL of Eu in fluoride nanoparticles has remained a huge challenge. Here, we propose a conceptual model to realize this aim by constructing the interfacial energy transfer in a core-shell nanostructure.

Full-color tuning in multi-layer core-shell nanoparticles from single-wavelength excitation.

Lanthanide-based luminescent materials have shown great capabilities in addressing scientific problems encountered in diverse fields. However, achieving full-color switchable output under single-wavelength irradiation has remained a daunting challenge. Here we report a conceptual model to realize this aim by the temporal control of full upconversion evolution in a multi-layer core-shell nanostructure upon a single commercial 980-nm laser, instead of two or more excitation wavelengths as reported previously.

Achieving Room-Temperature Phosphorescence in Solution Phase from Carbon Dots Confined in Nanocrystals.

Carbon dots (CDs) have attracted growing interest in the construction of room-temperature phosphorescent (RTP) materials. However, in the solution phase of CDs, it is still challenging to obtain efficient and stable phosphorescent emission due to the intense quenching effect by dissolved oxygen and solvent molecules. Herein, we report robust phosphorescence in the solution phase, achieved by encapsulating citrate-derived CDs into NaYF nanocrystals via a one-step method of high-temperature coprecipitation.

Manipulating energy migration in nanoparticles toward tunable photochromic upconversion.

Smart control of energy interactions plays a key role in manipulating upconversion dynamics and tuning emission colors for lanthanide-doped materials. However, quantifying the energy flux in particular energy migration in the representative sensitizer-activator coupled upconversion system has remained a challenge. Here we report a conceptual model to examine the energy flux in a single nanoparticle by designing an interfacial energy transfer mediated nanostructure.

Cross Relaxation Enables Spatiotemporal Color-Switchable Upconversion in a Single Sandwich Nanoparticle for Information Security.

Smart control of ionic interaction dynamics offers new possibilities for tuning and editing luminescence properties of lanthanide-based materials. However, it remains a daunting challenge to achieve the dynamic control of cross relaxation mediated photon upconversion, and in particular the involved intrinsic photophysics is still unclear. Herein, this work reports a conceptual model to realize the color-switchable upconversion of Tm through spatiotemporal control of cross relaxation in the design of NaYF:Gd@NaYbF:Tm@NaYF sandwich nanostructure.

Carbon Dots in Hydroxy Fluorides: Achieving Multicolor Long-Wavelength Room-Temperature Phosphorescence and Excellent Stability via Crystal Confinement.

Carbon dots (CDs) have aroused widespread interest in the construction of room-temperature phosphorescent (RTP) materials. However, it is a great challenge to obtain simultaneous multicolor long-wavelength RTP emission and excellent stability in CD-based RTP materials. Herein, a novel and universal "CDs-in-YOHF" strategy is proposed to generate multicolor and long-wavelength RTP by confining various CDs in the Y(OH)F (YOHF) matrix.

Near-Infrared-Excited Multicolor Afterglow in Carbon Dots-Based Room-Temperature Afterglow Materials.

Room-temperature afterglow (RTA) materials with long lifetime have shown tremendous application prospects in many fields. However, there is no general design strategy to construct near-infrared (NIR)-excited multicolor RTA materials. Herein, we report a universal approach based on the efficient radiative energy transfer that supports the reabsorption from upconversion materials (UMs) to carbon dots-based RTA materials (CDAMs).

Red, orange, yellow and green luminescence by carbon dots: hydrogen-bond-induced solvation effects.

The mechanism of the solvation-dependent multicolor luminescence of carbon dots (CDs) is not clear, despite the fact that multicolor luminescent CDs have important applications in many fields. In this article, we report solvated chromogenic CDs with productivity of up to 57%. The luminescence of the CD particles exhibits a regular redshift in N,N-dimethylformamide (DMF), ethanol, water, and acetic acid.