Metal halide ionic octahedra, serving as the fundamental optoelectronic unit in halide perovskites, enable near-infrared (NIR) luminescence via transition-metal ion incorporation. However, their intrinsically low radiative efficiency and inadequate operational stability have posed significant challenges for practical implementation. In this work, we report the first successful synthesis of a highly stable Mo-doped Sn-based perovskite NIR emitter via a one-step hydrothermal approach, which exhibits unprecedented dual broadband NIR emission (800-1630 nm). The oxidation of Sn2+ induces the formation of mixed Mo4+/3+ valence states, while the synergy of lattice distortion, spin-orbit coupling, and vibronic coupling activates multiple d-d transitions. Specifically, they promote the 1T2g/1Eg -> 3T1g transition of Mo4+ and the Gamma 8(2T1g) ->Gamma 8(4A2g) transition of Mo3+, achieving a high photoluminescence quantum yield (PLQY) of 68% at room temperature. Notably, this NIR-emitting halide maintains 88% of its room-temperature emission intensity at 423 K, demonstrating exceptionally low thermal quenching. Moreover, the precise control of Mo doping level and the introduction of Sn2+ enable the systematic tailoring of the NIR-I/II luminescence. This breakthrough not only provides fundamental design principles for developing next-generation broadband NIR-I and II emitting material but also establishes a new application platform in night-vision and vascular imaging for optoelectronic devices with superior performance.

Surface modification strategies exhibit superior interface control capability and functional scalability, which can not only protect the structure and performance stability but also endow the materials with new features. In particular, surface modification plays an important role in performance optimization of inorganic phosphor materials to improve their luminous efficacy, thermal stability, chemical resistance and compatibility. This strategy can promote a wide range of studies in light-emitting diodes, optical sensing, anti-counterfeiting, and biomedical imaging fields. Nevertheless, a profound understanding of the effects of surface modification on the structure and performance of phosphor materials is lacking. This review focuses on the recent advances in surface modification of the inorganic, organic, and organic-inorganic layer coatings of phosphor materials. The design principles, intrinsic structure variations, luminescence performance, underlying mechanisms and applications are comprehensively summarized. Notably, the relationship between interface engineering and luminescence optimization is proposed. Furthermore, we highlight the challenges faced by the coated phosphors in emerging fields and discuss the limitations of the current cladding technologies. This review provides new perspectives for the design of multifunctional phosphor materials with surface modification for advanced emerging platforms, and the proposed interface engineering mechanism offers theoretical guidelines for the performance manipulation of other functional materials.

Chiral three-dimensional (3D) metal halide frameworks (MHFs) merge semiconductor properties with chiroptical activity, offering a promising platform for advanced optoelectronics. However, synthesizing MHFs that are simultaneously 3D, chiral, and highly emissive remains a challenge. Herein, we report a synergistic strategy employing chiral organic cations as symmetry-breaking inducers and alcohol molecules as coordinating solvents to construct the first family of cerium halide dodecahedra-based chiral 3D MHFs. These chiral 3D MHFs integrate intrinsic chirality, spiral channels, and rare ths-type topology, exhibiting efficient ultraviolet emissions with near-unity photoluminescence quantum yield. Furthermore, precise modulation of the coordinating alcohol molecules enables enhanced geometric polyhedron distortion within the lattice, leading to amplified circularly polarized luminescence (CPL) with a dissymmetry factor reaching +/- 7.0 & times; 10-3. Thus, the best-performing 3D MHFs achieve a record figure of merit in ultraviolet CPL, creating a new platform for chiral photonic applications.

Near-infrared-II (NIR-II, 1000-1700 nm) luminescence is pivotal for advanced imaging and photonic technologies, with emission linewidth serving as a critical performance determinant. Typically, rare-earth ions enable sharp NIR-II emission via f-f transitions, which are constrained by their intrinsically small absorption cross-sections. As an emerging alternative, Mo3+-based perovskite systems with intra-configurational spin-flip (ICSF) transitions offer a promising route to ultra-narrowband NIR-II emission, yet achieving stable emission under ambient conditions remains a major challenge. Here we report the successful stabilization of Mo3+ ions in a series of quadruple perovskites, Cs4Cd1-xMnx(Sb/Bi)2Cl12 (x = 0-1.0), via a SnCl2-assisted hydrothermal method. This series luminescent materials exhibit characteristic ultra-narrowband NIR-II emission (~1093 nm) and a unique dual emission covering the deep-red (690-740 nm) and NIR-II regions (1050-1150 nm) at low temperatures. Systematic co-doping with Mn2+ is demonstrated to significantly enhance the Mo3+ emission via an efficient energy transfer process, achieving a maximum energy transfer efficiency of 86 % and a photoluminescence quantum yield of 74 %. Finally, NIR-II phosphor-converted light-emitting diodes (pc-LEDs) were fabricated, demonstrating promising performance in non-destructive testing, security screening, agricultural sorting, and biomedical imaging. This work provides a stable, efficient NIR-II luminescence platform and advances understanding of energy transfer in Mo3+-doped perovskites.

Multi-resonance thermally activated delayed fluorescence (MR-TADF) emitters are promising candidates for high-definition organic light-emitting diodes (OLEDs) and display, yet their long triplet state lifetime and slow reverse intersystem crossing (RISC) processes always lead to severe device efficiency roll-off. Herein, a synergistic phenylphosphine oxide/sulfide-locking/ heavy-atom strategy is proposed to rigidify the boron/nitrogen-fused MR-TADF frameworks and strengthen their spin–orbit coupling (SOC) effect. Four green emitters, BNPXZ-PO, BNPXZ-PS, BNPTZ-PO, and BNPTZ-PS, are constructed from 3,6-di-tert-butylcarbazole paired with phenoxazine or phenothiazine moieties. The meta-linked P=O/ PS unit and heavy-atom effect boost SOC and restrain vibrational relaxation, resulting in high kRISCs of up to 1.98 × 105 s−1 and photoluminescence efficiencies reaching 93%. Corresponding OLEDs show impressive performances, achieving maximum external quantum efficiencies (EQEmaxs) spanning 24.8–30.8%. Further TADF-sensitized devices realize elevated EQEmaxs of up to 35.2% with suppressed efficiency roll-off. Notably, BNPTZ-PS incorporating PS and phenothiazine segments affords the optimal photophysical and device characteristics. These results demonstrate that integrating phosphorus-locking motifs with moderate heavy-atom engineering represents an effective molecular design strategy to concurrently accelerate exciton upconversion, boost device efficiency and alleviate efficiency roll-off for MR-TADF emitters.

Vector vortex beams have attracted extensive attention due to their promising applications in optical manipulation, optical communication, and high-dimensional information processing. However, efficient generation and flexible control of high-order vector vortex beams in the terahertz regime remain challenging. In this work, we propose and experimentally demonstrate a terahertz 3D-printed all-dielectric metasurface platform for polarization-selective manipulation of vector vortex beams at 0.1 THz. By jointly engineering geometric phase and propagation phase, multi-degree-of-freedom control of the output beams is achieved. Three metasurface samples are designed and fabricated to realize the generation of first- and second-order vector vortex beams with controllable orbital angular momentum states and focusing characteristics under different incident polarization conditions. Both numerical and experimental results demonstrate that the proposed metasurfaces can effectively generate radial and azimuthal vector vortex beams as well as spin-dependent vortex modes with opposite topological charges. In addition, the introduction of lens phase significantly improves the spatial energy concentration and focusing performance of the generated beams. The proposed strategy provides a feasible platform for terahertz vector beam manipulation and may find potential applications in high-dimensional information encoding, optical field regulation, and terahertz integrated photonic systems.

Development of efficient and structurally stable zero-dimensional (0D) hybrid antimony halide materials still encounters huge challenges due to the limited and time-consuming trial-and-error design principle. Here, a host-guest chemistry strategy is employed at the A-site to design a series of hybrid antimony-based bimetallic halides (HABHs) with a general formula of [A(L)6][BCln] (A = lanthanide and alkaline earth metals; B = Sb, In, and Bi; and L = urea ligands with different substituents). Controllable structural regulation is achieved by adjusting the steric effect of large [A(L)6]2+/3+ clusters, realizing a wide photoluminescence (PL) spectral modulation and high photoluminescence quantum efficiency (PLQY) over 98%. Some photophysical properties could be well correlated with specific structural changes. The PL spectral profile and emission energy are mainly dependent on the distortion of the SbCln polyhedra. In particular, a quantitatively exponential relationship between PLQY and structural parameters (bond distortion, angle deviation, and the defined effective Cl number describing the integrity of the hydrogen bonding network) related to the [SbCln](n-3)- sublattice has been reasonably established. As supported by theoretical calculations and photophysical analysis, strong exciton localization with negligible nonradiative recombination has been demonstrated for high PLQY, which results from a highly symmetrical rigid structure and the "shielding effect" of a complete hydrogen bonding network. Environmental stability and unique temperature-dependent PL behaviors enable multiapplications. This work proposes a quantitative "structure-property" correlation insight for new hybrid antimony halides, providing a direction for advancing the design of efficient hybrid metal halide materials.

Lead-free halide double perovskites (LFHDPs) have gained prominence as eco-friendly optoelectronic materials due to their structural stability and flexible tunability. Lanthanide (Ln3+) ions have rich energy levels, which can endow LFHDP materials with emissions ranging from visible to near-infrared (NIR) region through the ion doping strategy. However, their NIR applications remain limited by narrowband emission and low photoluminescence quantum yield (PLQY) due to weak absorption cross-section. Herein, Cs2NaInCl6:Ln3+ were successfully synthesized, and the problem of low absorption of Ln3+ ions is effectively solved. Incorporating Mo4+/Ag+ ions achieves a near-unity PLQY and expands the excitation spectrum across the full visible range and a small part of NIR region (250–850 nm). Mechanism analysis revealed synergistic energy transfer pathways involving self-trapping excitons and intermediate energy states of Mo4+ ion, enhancing both photon absorption and PLQY. The universal applicability of this approach has been validated across Bi-based and multiple lanthanide ions (Ln: Ho, Er, Tm, Yb). These optimized materials demonstrate exceptional broadband emission characteristics suitable for multi-scenario NIR applications, including light-emitting-diodes (LEDs), night vision, imaging, anti-counterfeiting technologies. This co-doping methodology establishes a versatile framework for overcoming inherent limitations in Ln3+-activated materials, offering new possibilities for efficient NIR optoelectronic devices. The synthesis of Ag+/Mo4+/Ln3+ co-doped double perovskite has yielded exceptional optical properties, including broadband excitation and highly efficient NIR luminescence. These advances demonstrate promise for versatile photoelectric applications and provide critical insights into optimizing lanthanide absorption by two-step enhancement strategy.

ABSTRACT Hydrogen‐bonding interactions between chiral organic and inorganic components have been widely utilized to induce and modulate circularly polarized luminescence (CPL) in chiral hybrid metal halides (CHMHs). Beyond these established strategies, incorporating inter‐octahedral (inorganic‐inorganic) hydrogen bonding offers significant yet underexplored potential for amplifying CPL through long‐range chirality transfer. Here, we report the design and synthesis of ( S / R ‐C 9 H 20 ON 2 )In 0.93 Sb 0.07 Cl 5 ·H 2 O ( S / R ‐InSbCl 5 ·H 2 O), in which three types of organic‐inorganic, inter‐octahedral, and inter‐organic (organic‐organic) hydrogen‐bonding interactions are synergistically integrated within a zero‐dimensional CHMH framework. These materials not only feature a near‐unity photoluminescence quantum yield, but also, more importantly, exhibit a remarkable luminescence dissymmetry factor of 0.1. Structural and photophysical analyses reveal that inter‐octahedral hydrogen bonding significantly enhances octahedral distortion and the coherence of chirality transfer across the lattice through inter‐octahedral interactions, thereby significantly amplifying CPL activity. Combined crystallographic analyses and theoretical calculations further demonstrate that these interactions are governed by the electrostatic potential distribution of coordinated molecules and the inter‐octahedral distance. This work highlights inter‐octahedral hydrogen bonding as a novel key structural parameter for CPL amplification and provides a general strategy for designing high‐performance chiral luminescent materials.

Achieving tunable emission in single-halide perovskite nanocrystals via size control remains challenging, while mixed-halide alternatives suffer from inherent instability. Here, we establish a synergistic ligand engineering strategy for the controlled synthesis of atomically layered quasi-2D perovskite nanosheets in pure-iodide systems. By systematically comparing the roles of amine (OLA, PEA) and ammonium (PEAI, CMAI) ligands, we demonstrate that PEAI and CMAI terminate vertical growth via strong surface binding from the –NH3+ group, while OLA prevents nanocrystal aggregation, which is a complementary function essential for achieving well-dispersed, ultrathin nanosheets. Through combined ligand and solvent engineering, we achieve precise thickness control from n = 1 to n = 8 with tunable emission across 527–729 nm, a broader range than previously reported for single-halide colloidal perovskite nanosheets. Notably, CMAI-passivated n = 3 nanosheets exhibit superior stability, retaining 71% of initial PL in a 1:2 (v/v) aqueous environment after 35 min and 38.1% after 15 min of intense 405 nm laser irradiation (49 mW), significantly outperforming both OLA- and PEAI-based analogues. This work establishes a dual-ligand synergistic framework that overcomes the long-standing challenges of thickness control and spectral tunability in single-halide perovskite nanosystems, providing a generalizable strategy for designing stable, high-performance perovskite optoelectronic materials.© 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Global Science and Technology Forum Pte Ltd.

Chiral hybrid metal halides (CHMHs) have emerged as a promising class of ionic crystalline materials for circularly polarized luminescence (CPL). In these materials, organic cations primarily act as chirality sources, whereas the inorganic frameworks serve as the luminescent centers. The interactions between chiral organic cations and inorganic frameworks enable intrinsic CPL emission. The soft and ionic nature of CHMHs further distinguishes them from conventional covalent luminophores, offering exceptional structural and chiroptical tunability. This tutorial review summarizes recent progress in CPL-active CHMHs, focusing on the fundamental routes for CPL generation, amplification and application. Representative synthetic strategies for CHMHs are introduced, followed by an analysis of luminescence mechanisms and their relevance to CPL generation. Key strategies to enhance CPL performance, including composition engineering and external-field regulation, are also reviewed. Beyond fundamental understanding, emerging applications enabled by the unique properties of CHMHs, including circularly polarized light-emitting diodes, CPL-resolved scintillators, and anti-counterfeiting technologies, are summarized. Finally, key challenges and future perspectives are outlined to guide the development of high-performance CHMH-based chiroptical materials and devices.

ABSTRACT Circularly polarized luminescence (CPL) provides an additional degree of freedom for light manipulation beyond intensity and wavelength and is essential for advanced photonic technologies. Chiral hybrid metal halides (HMHs) have recently emerged as promising CPL‐active materials. However, the simultaneous realization of high efficiency near‐infrared (NIR) emission and strong CPL remains challenging. Here, we report an enantiomeric pair of zero‐dimensional hybrid copper bromides, (18C6@ S/R ‐CHEA) 2 Cu 4 Br 6 (abbreviated as S/R ‐CHEACuBr, 18C6 = 18‐crown‐6, S/R ‐CHEA = ( S/R )‐1‐cyclohexylethanamine), in which protonated S/R ‐CHEA + is coordinated with 18C6 to form the bulky umbrella‐type supramolecular cations. Such unique cations effectively isolate the inorganic [Cu 4 Br 6 ] 2− emissive clusters and induce pronounced distortions of inorganic clusters. As a result, the obtained materials show strong circularly polarized near‐infrared (CP‐NIR) emission with photoluminescence quantum yields exceeding 50% and a high dissymmetry factor up to 6.8 × 10 −2 . Furthermore, light‐emitting diodes based on these materials exhibit high output power and distinct CP‐NIR signals, offering new opportunities for NIR imaging and secure information technologies.

Persistent radicals, species with unpaired electrons, are pivotal for advanced optical and electrical applications but are challenging to stabilize. Herein, we report a melt-quenching vitrification strategy that stabilizes persistent organic radicals within chiral zero-dimensional hybrid zinc chloride glasses, overcoming their intrinsic instability. These radicals are generated via deprotonation-induced organic cations during the vitrification process and are subsequently trapped within the glassy matrix, where they function as continuous electron donors. Compared to crystalline hybrid zinc chloride counterparts, the radical-containing glasses exhibit attractive luminescent properties: a 25-fold enhancement in long lifetime with ultralong persistent luminescence, a 4-fold increase in photoluminescence quantum yield, exceptional thermal emission stability, pronounced circularly polarized luminescence, and a 4 orders of magnitude enhancement in electrical conductivity. This work establishes melt-quenching vitrification as a novel strategy for stabilizing persistent radical materials with integrated functionalities.

Despite the exceptional optoelectronic properties of three-dimensional (3D) perovskites, their commercial application remains constrained by insufficient long-term stability. Low-dimensional (LD)@3D perovskites integrate the high efficiency of 3D frameworks with the superior stability of LD phases, presenting a highly promising architecture. Herein, a series of aromatic heterocyclic imidazole derivatives, specifically 1H-benzo[d]imidazole hydroiodide (BnI), 3H-imidazo[4,5-b]pyridine hydroiodide (PdI), and 1H-imidazo[4,5-b]pyrazine hydroiodide (PzI), are tailored and incorporated into perovskite precursors as additives, promoting the formation of LD@3D perovskites. The LD perovskites can effectively passivate defects at the grain boundary and interface, optimize energy level alignment, and improve hole extraction. As a result, the champion perovskite solar cells (PSCs) based on PzI achieve an excellent power conversion efficiency (PCE) of 25.63%. Meanwhile, the unencapsulated devices with PzI display superior long-term stability, which retain 90% of their initial PCE after 1600 h in ambient air. Finally, this strategy is successfully scaled to minimodules, delivering an efficiency of 21.51% for an active area of 20.25 cm2, which is a very competitive efficiency in minimodules. This study highlights the pivotal role of rational additive engineering in LD@3D perovskites, demonstrating that tailored molecular design for highly efficient and stable PSCs.

Thermal quenching remains a pivotal challenge that limits the further application of near-infrared luminescent materials. Herein, we report a zero thermal quenching emission based on La3SbO7 host with highly symmetric site for Nd3+ ions. Under the excitation of 808 nm laser, the integrated emission intensity of La3SbO7:0.01Nd3+ phosphor maintained 101% and 96% of the initial intensity at 473 and 513 K, respectively. The calculated temperature-dependent luminescence decay lifetimes also maintain around 0.21 ms and show a trend of no decline as a function of temperature, demonstrating an extremely superior thermal stability. Besides, compared with Lu3SbO7 structure and other activator ions, it can be found that thermal stability is closely connected with local structure characteristics and the process of energy transfer. Finally, by employing a 808 nm chip, the prepared near-infrared phosphor-converted light-emitting diode presents great potential for night vision. This work provides a feasible idea for accelerating the discovery of NIR emitting oxide luminescent materials with excellent thermal stability.

The stability of conventional hole transport materials (HTMs, e.g., Spiro‑OMeTAD) in n‑i‑p perovskite solar cells (PSCs) remains a critical challenge, particularly due to the unstable nitrogen‑centered radical cations ([Ar3N]·+) generated during their p‑type doping oxidation. Herein, three indenofluorene (IF)-based HTMs substituted with fluorene and 1,4-dithiafulvalene (DTF) units were designed and synthesized, denoted IF‑FF, IF‑TF and IF‑TT. The incorporation of the DTF unit endows IF‑TT with improved planarity, optimized energy‑level alignment, enhanced stacking orientation, and effective interfacial passivation. More importantly, through cooperative doping‑oxidation with Magic Blue and LiTFSI, IF‑TT generates highly delocalized, structurally stable sulfur‑centered radical cations ([DTF]·+), which greatly accelerates the post-oxidation process. Notably, IF‑TT·+ exhibits stronger interaction with LiTFSI than Spiro‑OMeTAD·+, resulting in a higher concentration of more stable radicals upon doping. Consequently, IF‑TT displays superior doping stability and charge‑transport properties. As a result, IF‑TT‑based PSCs achieve a remarkable power conversion efficiency of 25.89%, outperforming Spiro‑OMeTAD‑based devices (25.29%). Furthermore, the enhanced radical stability and improved film characteristics endow IF‑TT‑based devices with exceptional operational stability. This study highlights that stabilizing the radical species generated during doping is a key strategy for synergistically improving both the efficiency and long‑term stability of PSCs.

Correction for ‘Photochemical upcycling of polymers via visible light-driven C–H bond activation’ by Yi Wei et al., Chem. Commun., 2025, https://doi.org/10.1039/D4CC05866F.

Chiroptical waveguides, capable of generating and propagating circularly polarized light (CPL), hold significant promise for next-generation optoelectronic devices. However, developing novel, efficient chiroptical waveguides remains challenging, due to the difficulty of integrating strong intrinsic chiroptical activity with efficient directional light transport within a single crystalline material. Here, we report a new enantiomeric pair of chiral hybrid metal halides, ( S/R -C 5 H 14 N 2 )CuAgBr 4 ( S/R -CuAg), featuring a one-dimensional inorganic structure. Ag incorporation enhances photoluminescence quantum yield from 0.6% to 18.6%, while enabling bright CPL emissions with dissymmetry factors ( g lum ) of ± 7 × 10 −3 . The tightly packed inorganic lattice and highly anisotropic microstructure of S/R -CuAg exhibit a low optical loss coefficient of 9.6 × 10 −3  dB µm −1 . Crucially, microrod crystals of S/R -CuAg function as efficient chiroptical waveguides, simultaneously emitting and propagating CPL under unpolarized light excitation. This work establishes chiral hybrid metal halides as a viable platform for circularly polarized waveguide applications.