All-inorganic CsPbX₃(X = Cl, Br, and I) perovskite quantum dots (PeQDs) have shown great promise in optoelectronics and photovoltaics owing to their outstanding linear optical properties; however, nonlinear upconversion is limited by the small cross-section of multiphoton absorption, necessitating high power density excitation. Herein, we report a convenient and versatile strategy to fine tuning the upconversion luminescence in CsPbX₃PeQDs through sensitization by lanthanide-doped nanoparticles. Full-color emission with wavelengths beyond the availability of lanthanides is achieved through tailoring of the PeQDs bandgap, in parallel with the inherent high conversion efficiency of energy transfer upconversion under low power density excitation. Importantly, the luminescent lifetimes of the excitons can be enormously lengthened from the intrinsic nanosecond scale to milliseconds depending on the lifetimes of lanthanide ions. These findings provide a general approach to stimulate photon upconversion in PeQDs, thereby opening up a new avenue for exploring novel and versatile applications of PeQDs.

Impurity doping is an effective approach to tuning the optoelectronic performance of host materials by imparting extrinsic electronic channels. Herein, a family of lanthanide (Ln³⁺) ions was successfully incorporated into a Bi:Cs₂AgInCl₆ lead-free double-perovskite (DP) semiconductor, expanding the spectral range from visible (Vis) to near-infrared (NIR) and improving the photoluminescence quantum yield (PLQY). After multidoping with Nd, Yb, Er and Tm, Bi/Ln:Cs₂AgInCl₆ yielded an ultrabroadband continuous emission spectrum with a full width at half-maximum of ~365 nm originating from intrinsic self-trapped exciton recombination and abundant 4f–4f transitions of the Ln³⁺ dopants. Steady-state and transient-state spectra were used to ascertain the energy transfer and emissive processes. To avoid adverse energy interactions between the various Ln³⁺ ions in a single DP host, a heterogeneous architecture was designed to spatially confine different Ln³⁺ dopants via a “DP-in-glass composite” (DiG) structure. This bottom-up strategy endowed the prepared Ln³⁺-doped DIG with a high PLQY of 40% (nearly three times as high as that of the multidoped DP) and superior long-term stability. Finally, a compact Vis–NIR ultrabroadband (400~2000 nm) light source was easily fabricated by coupling the DiG with a commercial UV LED chip, and this light source has promising applications in nondestructive spectroscopic analyses and multifunctional lighting.

The launch of the big data era puts forward challenges for information preservation technology, both in storage capacity and security. Herein, a brand new optical storage medium, transparent glass ceramic (TGC) embedded with photostimulated LiGa₅O₈: Mn²⁺ nanocrystals, capable of achieving bit-by-bit optical data write-in and read-out in a photon trapping/detrapping mode, is developed. The highly ordered nanostructure enables light–matter interaction with high encoding/decoding resolution and low bit error rate. Importantly, going beyond traditional 2D optical storage, the high transparency of the studied bulk medium makes 3D volumetric optical data storage (ODS) possible, which brings about the merits of expanded storage capacity and improved information security. Demonstration application confirmed the erasable–rewritable 3D storage of binary data and display items in TGC with intensity/wavelength multiplexing. The present work highlights a great leap in photostimulated material for ODS application and hopefully stimulates the development of new multi-dimensional ODS media.

We report the controlled synthesis of monodisperse NaCeF ₄ :Er/Yb nanoprobes that exhibit intense NIR-II emission for in vitro bioassay and in vivo bioimaging.

One batch yield as high as 63.38 g of uniform lanthanide-doped NaREF₄ nanoprobes was achieved via a novel solid–liquid-thermal-decomposition strategy.