Donglei Zhou

Metal‐organic frameworks (MOFs) are widely deployed in catalysis, separation and chemical sensing, yet luminescent MOFs, especially those emitting near‐infrared (NIR) circularly polarized luminescence (CPL), remain largely underexplored. Here, we address this critical gap through a hierarchical dual‐sphere engineering strategy to fabricate luminescent Eu‐Yb‐BTC MOFs, wherein L‐phenylalanine serves as a second‐sphere modulator to construct low‐symmetry chiral microenvironments surrounding lanthanide centers. Subsequent hybridization with Yb‐doped perovskite quantum dots synergistically enhances both quantum‐cutting efficiency and CPL performance, yielding a 170% enhancement in the 980 nm Yb ³⁺ emission, an absolute photoluminescence quantum yield of 154%, and a luminescence dissymmetry factor of ‐1.58 × 10 ⁻² . Leveraging its single‐source RED‐NIR dual‐band CPL output, whose inherent polarization selectivity suppresses stray light and ambient background noise to enable more accurate blood oxygen monitoring, we demonstrate a portable blood oxygen sensor with 15 s response and <1.5% measurement error, and further develop an AI‐assisted emotion recognition framework based on dual‐channel photoplethysmography signals. This work establishes a versatile design paradigm for high‐performance chiral luminescent MOFs, opening new avenues for next‐generation wearable biomedical diagnostics and edge‐AI‐enabled healthcare.

Ytterbium-ion (Yb3+)-doped quasi-2D layered metal halide perovskites (quasi-2D LMHPs) stand out as a transformative platform for near-infrared (NIR) emissions beyond 950 nm, holding great promise for revolutionizing next-generation photonic systems. Herein, we report a synergistic engineering strategy to simultaneously regulate phase distribution in the emissive layer and carrier transport in the hole-transport layer, enabling record-performance NIR perovskite light-emitting diodes (PeLEDs) emitting at 986 nm. The incorporation of fluorinated aromatic spacers (p-F-PEA+) and partial formamidinium (FA+) substitution strengthens organic–inorganic interactions, affording well-controlled phase distribution and highly efficient exciton-to-Yb3+ energy transfer. Meanwhile, zwitterionic kanamycin is introduced to neutralize the intrinsic acidity of PEDOT:PSS via distinct chemical interactions, leading to balanced carrier injection and suppressed nonradiative recombination. Benefiting from this dual-layer modulation, the optimized Yb3+-doped (PEA1.8p-F-PEA0.2)(Cs1.6FA0.4)Pb3Br10 PeLEDs exhibit a record peak NIR external quantum efficiency (EQE) of 12.1% at 986 nm and an outstanding operational half-life (T50) of 1823 min. More critically, we break the scalability bottleneck of NIR PeLEDs with 300 mm2 large-area devices delivering a state-of-the-art EQE of over 7.5%. We pioneer a visible/NIR dual-mode display and imaging platform via patterned PeLEDs, integrating explicit visible identification and covert NIR high-security anticounterfeiting. This work broadens the application prospects of NIR PeLEDs in high-security anticounterfeiting, nondestructive imaging, and smart photonic systems.

Lead‐free rare‐earth‐based halide perovskite have emerged as a promising candidate for near‐infrared light‐emitting diodes (NIR‐LED), yet their development has been hindered by inefficient energy transfer and severe non‐radiative losses. Here, we report a comprehensive optimization strategy for Cs ₃ YbBr ₆ :Er ³⁺ nanocrystals through Sb ³⁺ sensitization and niacin passivation, achieving record‐breaking electroluminescence performance. Systematic investigations reveal that Yb ³⁺ serves as a critical energy transfer bridge, with optimal 5% Er ³⁺ doping yielding a PLQY of 20.34% at 1540 nm. The introduction of Sb ³⁺ as an efficient sensitizer captures free exciton and enhances energy transfer, boosting the 1540 nm PLQY to 36.6%. First‐principles calculations demonstrate that Sb ³⁺ incorporation reduces the bandgap and promotes charge localization around [SbBr ₆ ] ³⁻ octahedra. Furthermore, niacin molecules selectively passivate undercoordinated Yb ³⁺ sites via carboxyl coordination, reducing film roughness, decreasing trap densities, and achieving balanced carrier mobilities. The resulting LED exhibits multi‐wavelength emissions, peaking at 470 nm, 980 and 1540 nm, respectively. It demonstrates an external quantum efficiency of 9.96% and exceptional operational stability of 753 min (T ₅₀ ), representing the highest efficiency reported for various rare‐earth‐based perovskite LEDs. A practical infrared imaging system is successfully demonstrated, highlighting the potential of this materials platform for next‐generation optoelectronic applications.

Near-infrared (NIR) electroluminescence at 1.54 μm is vital for optical communication and bioimaging. Although CsPbCl3:Yb3+, Er3+ perovskite quantum dots (PQDs) represent a promising emitter platform, their device efficiency is hindered by intrinsically weak Er3+ emission. Here, we achieve highly efficient 1.54 μm electroluminescence via a bulk-surface dual-reconstruction strategy. Within the lattice interior, Na+ incorporation fills Pb vacancies and perturbs local crystal-field symmetry, suppressing non-radiative decay while enhancing the Er3+ and Yb3+ radiative transition rates by 7.83-fold and 3.30-fold, respectively. This boosts the Yb3+-to-Er3+ energy transfer efficiency from 15% to 56.6%. Concurrently, at the PQD surface, passivation with trifluoromethanesulfonate (OTF-) eliminates halogen vacancies via robust Lewis acid--base coordination, yielding a 45% photoluminescence quantum yield (PLQYs) at 1.54 μm. Consequently, the optimized NIR perovskite light-emitting diodes deliver a 3.27% external quantum efficiency, a 2.03 mW sr–1 cm–2 peak radiance, and an operational half-life exceeding 120 min.

Tin dioxide (SnO ₂ ) is widely used as the electron transport layer (ETL) in n‐i‐p type perovskite solar cells (PSCs), yet its practical potential is plagued by intrinsic oxygen vacancies and structural defects arising from chemical bath deposition (CBD). Herein, we propose a facile pretreatment strategy: integrating water‐soluble terbium oxide nanocrystalline (Tb ₂ O ₃ NCs) into the CBD‐derived SnO ₂ ETLs post‐cleaning but pre‐annealing. Systematic characterizations confirm that Tb ₂ O ₃ NCs induce a homogeneous SnO ₂ ‐Tb ₂ O ₃ composite interface via lattice oxygen‐mediated interfacial interaction. The abundant lattice oxygen of Tb ₂ O ₃ NCs mediates the passivation of SnO ₂ oxygen vacancies by replenishing oxygen defects. Meanwhile, the lattice oxygen‐regulated composite ETL exhibits enhanced carrier mobility, reduced surface roughness, and optimized surface energy, which synergistically promote perovskite crystallization into large‐grain films with superior light‐trapping capability. Consequently, the target PSCs achieve a champion power conversion efficiency (PCE) of 25.95%. Furthermore, the lattice oxygen‐mediated interfacial bonding mitigates ETL tensile strain under thermal cycling. These synergistic merits significantly enhance the device's humidity stability and operational stability in ambient air. This work provides a facile and scalable strategy to simultaneously engineer the defect state and structural integrity of SnO ₂ ETLs, offering valuable insights for the rational design of high‐efficiency and stable PSCs.

Er ³⁺ ‐doped 1540 nm light‐emitting diodes (LEDs) are critical components in optical communications C‐band, non‐trunk communication, bioimaging, and sensing. However, integrating high luminous efficiency with tailored circularly polarized luminescence (CPL) in such LEDs remains a critical challenge. Here, we demonstrate efficient 1540 nm short‐wave infrared (SWIR) electroluminescence with distinct CPL in Cs ₃ ErCl ₆ nanocrystals (NCs)‐based LEDs via a synergistic strategy of Sb ³⁺ /Y ³⁺ co‐doping and camphor ligand modification. Y ³⁺ doping modulates lattice symmetry, inducing Stark splitting of the Er ³⁺ energy level and enhancing luminescence intensity. Sb ³⁺ introduction triggers efficient self‐trapped excitons emission at 530 nm, whose energy levels match Er ³⁺ states to boost energy transfer efficiency. Subsequently, camphor ligand exchange passivates Er ³⁺ ‐related defects, increasing the 1540 nm photoluminescence quantum yield to 35.7% and endowing NCs with CPL (asymmetry factor: −3.67 × 10 ⁻² ) via camphor's chiral structure. SWIR LEDs based on camphor‐modified Cs ₃ Er _0.7 Y _0.3 Cl ₆ : Sb ³⁺ NCs exhibit a record‐high external quantum efficiency of 3.06% at 1540 nm, and first, demonstrate electrically‐driven circularly polarized 1540 nm emission with asymmetry factor of −3.08 × 10 ⁻² . This work presents a synergistic doping‐ligand strategy for Er‐based halide optoelectronics, offering a versatile platform to develop high‐performance long‐wavelength devices with integrated efficient emission and tailored polarization, crucial for advancing next‐generation optical communication and bioimaging.

The pursuit of wideband tunable near-infrared (NIR) light sources has reached fever pitch due to advances in photonic chips, optical communications, and molecular trace detection. Lanthanide ions (Ln³⁺), renowned for their characteristic NIR luminescence, have nevertheless been stymied by the challenges of an extremely low molar extinction coefficient and linear absorption. Herein, a senitization methodology is presented that capitalizes on the quantum cutting-engineered heterostructure nanoparticles (CsPbX₃: Yb³⁺-NaYF₄: Yb³⁺, Ln³⁺), to achieve multi-wavelength NIR luminescence spanning the 900-2200 nm spectrum. The designed heterostructure exhibits an unprecedented absorption bandwidth (200–690 nm) across the UV-visible spectrum, with an exceptionally low stimulation threshold at the sub-microwatt level (50 µW cm^-2). The NIR luminescent wavelengths can be precisely modulated by meticulously adjusting the dopant Ln³⁺ ions leveraging Yb³⁺-mediated quantum cutting processes. Spectroscopic analysis reveals a directed energy transfer pathway at the perovskite-fluoride heterogeneous interface: perovskite host→Yb³⁺ (perovskite) →Yb³⁺ (NaYF₄) → Ln³⁺. This architecture demonstrates multiplexed gas detection capabilities under AI-assisted analysis, facilitating the simultaneous identification and monitoring of multiple marker gases in complex environments. Our work provides a scalable strategy for constructing ultra-broadband NIR light sources, with implications for high-throughput spectroscopic sensing.

Intrinsic defects and environmental instability remain critical bottlenecks for perovskite solar cells (PSCs). Here, we report the deployment of heme (C ₃₄ H ₃₂ FeN ₄ O ₄ )—as a dual‐function modifier to concurrently address defect passivation and oxidative stability. The molecular architecture of heme, featuring redox‐active Fe ²⁺ centers and conjugated porphyrin rings, enables Lewis acid‐base coordination with undercoordinated Pb ²⁺ /I ⁻ at grain boundaries, reducing trap‐state density by 60% and promoting uniform crystal growth. This results in a significant power conversion efficiency (PCE) enhancement from 21.53% to 24.71% via suppressed nonradiative recombination and improved charge extraction. Beyond efficiency improvements, the heme‐modified devices exhibit superior environmental stability enabled by dual protective mechanisms: the hydrophobic porphyrin framework reduces moisture ingress, while the redox‐active Fe ²⁺  center forms a sacrificial oxygen scavenging layer. Specifically, heme‐mediated oxidation (Fe ²⁺ →Fe ³⁺ ) preferentially consumes ambient oxygen, retarding perovskite degradation under aerobic conditions. As a result, the modified devices retain 91.6% of their initial PCE after 3500 h of continuous air exposure without encapsulation, showcasing a 3‐fold improvement in oxygen tolerance compared to pristine devices. This work leverages metalloporphyrin structures to address both efficiency and stability bottlenecks in PSCs, demonstrating that rational molecular design inspired by biological redox systems can propel effective solutions for next‐generation photovoltaic technologies.

High‐efficiency near‐infrared (NIR) light‐emitting diodes (LEDs) operating in 800‐2000 nm spectral window are pivotal for advancing optical communication, biomedical imaging, and security sensing. Here, a strategy using double perovskite Cs ₂ AgInCl ₆ nanocrystals co‐doped with Bi ³⁺ , Yb ³⁺ , and heavily doped Er ³⁺ is demonstrated to achieve efficient long‐wavelength NIR emission. The double perovskite host with self‐trapped excitons (STEs) property serves as an energy reservoir for subsequent transfer to Er ³⁺ . Bi ³⁺ doping induces lattice distortion, enhancing STEs formation and breaking octahedral symmetry around Er ³⁺ to boost the ⁴ I _13/2 → ⁴ I _15/2 transition. Yb ³⁺ as a sensitizer, bridges the energy gap between STEs and Er ³⁺ , facilitating efficient energy transfer to populate Er ³⁺ metastable states. This synergistic mechanism, enabled by double perovskite's broadband emission and homovalent doping tolerance, allows heavy Er ³⁺ loading (≥20% molar‐ratio), driving a photoluminescence quantum yield of 31% at 1540 nm. NIR LEDs fabricated with these nanocrystals achieve a champion external quantum efficiency (EQE) of 1.79% at 1540 nm (average EQE: 1.49%) and maintain 50% emission intensity for 3.3 h under continuous operation. This work establishes double perovskites as a versatile platform for STEs‐mediated NIR emission, offering a new paradigm for designing high‐performance long‐wavelength optoelectronic devices.

Photocatalytic CO2 reduction for solar fuel generation is a promising approach to alleviating the environmental and energy crisis. Herein, a flower-like composite was obtained by assembling Zn vacancy-rich ZnIn2S4 (VZn-ZIS) with up-conversion nanoparticles (UCNPs, NaYF4: Yb, Er). Specifically, the optimized UCNPs@VZn-ZIS demonstrates superior CO generation of 32.57 μmol/g in the near-infrared (NIR)-driven photocatalytic CO2 reduction process within 8 h. Fortunately, the performance of photocatalytic CO2 reduction based on optimized UCNPs@VZn-ZIS is superior to most reported photocatalysts under NIR irradiation. The enhanced photocatalytic CO2 reduction activity is attributed to the extended light absorption, enhanced charge separation, and improved CO2 activation of the surface vacancy. The work presented here provides a facile approach to developing novel broad spectral responsive photocatalytic CO2 reduction photocatalysts, which hold great potential for solar fuel generation in future applications.