Key Takeaways & Executive Findings
- •• • Cosubstitution of Ca2+ and Sn4+ in Y3Ga5O12:Cr3+ garnet shifts emission peak from 708 to 768 nm, enabling spectral tunability for plant lighting (Pfr absorption). • • Optimized phosphor Y2.6Ca0.4Ga4.6Sn0.4O12:0.07Cr3+ achieves EQE of 34.96%, a 2.71-fold intensity enhancement over the unsubstituted host, attributed to octahedral Jahn-Teller distortion. • • Thermal stability reaches 91.3% at 423 K, owing to weak electron-phonon coupling and oxygen vacancy defects, ensuring reliable operation in high-temperature LED environments. • • NIR pc-LED device demonstrates electroluminescence efficiency of 18.8% at 100 mA and <5% intensity loss after 30 days, validating long-term operational stability for agricultural lighting.
Abstract
Near-infrared (NIR) spectroscopy has significantly advanced NIR light sources, yet creating NIR emitters with optimal luminescence properties, high thermal stability, and adjustable emission peaks remains a critical challenge for future smart NIR devices. Here, we introduce a chemical unit cosubstitution strategy by incorporating Ca2+ and Sn4+ ions into the garnet structure. Through this approach, Y3−yCayGa4.95−ySnyO12:0.05Cr3+ (y = 0–1) phosphors were developed by modulating the A&C ligands, resulting in emission centers ranging from 708 to 768 nm. The modified local environment of Cr3+ accounts for the increased light intensity (2.71 times) and broadening observed. Furthermore, this study investigated the impact of varying Cr3+ concentrations (Y2.6Ca0.4Ga4.6−xSn0.4O12:xCr3+) on the production of high-performance phosphors. Compared with Y3Ga4.93O12:0.07Cr3+, the optimized phosphor exhibited exceptional external quantum efficiency (EQE = 34.96%). The luminescence enhancement is attributed to an increase in radiative transitions caused by octahedral Jahn-Teller distortion, whereas the notable thermal stability (91.3% at 423 K) is attributed to the presence of weak electron-phonon coupling (EPC) and oxygen vacancy (OV) defects. Finally, by combining it with a 450 nm blue LED chip, we constructed a near-infrared phosphor-converted LED (NIR pc-LED) device with superior electroluminescence efficiency (18.8% @ 100 mA), increasing the ultralow quenching rate (< 5% intensity loss after 30 days of operation) and demonstrating remarkable performance in plant lighting applications.
1. Introduction
Commercial NIR light sources, such as halogen lamps and semiconductor lasers, suffer from large form factors, low wall-plug efficiency, and poor spectral matching to plant photoreceptors. NIR pc-LEDs offer compactness and efficiency, but their performance hinges on phosphor properties: emission peak position, quantum efficiency, and thermal stability. Existing Cr3+-doped garnet phosphors often exhibit limited tunability or inadequate thermal quenching, hindering their adoption in precision agriculture and portable devices.
This work addresses these bottlenecks via a chemical unit cosubstitution strategy, replacing Y3+–Ga3+ pairs with Ca2+–Sn4+ in the garnet lattice. This approach modulates the crystal field around Cr3+ through A&C site engineering, achieving broad emission tunability (708–768 nm) and a 2.71-fold intensity increase. The optimized phosphor attains an EQE of 34.96% and retains 91.3% of its room-temperature intensity at 423 K, while the fabricated pc-LED shows 18.8% efficiency at 100 mA and negligible degradation over 30 days, demonstrating a viable path for high-performance plant lighting.
Loading authentic research manuscript (Pages 1–5)...
PENG Chunli, TANG Baoling, ZHANG Xuejie, MOLOKEEV Maxim S, ZHANG Haoran, LEI Bingfu (2026). Achieving High-Performance Near-Infrared Cr3+-Activated Phosphor via A&C Lattice Sites Cosubstitution Strategy in Garnet for Plant Lighting. SCIENCE CHINA Materials. https://doi.org/10.1007/s40843-025-3691-9
Research & Educational Purpose Only: The translations, structured abstracts, analytical annotations, and data reports provided by SinoGreenTechare intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoGreenTech claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What is the mechanism behind the emission peak shift from 708 to 768 nm upon Ca2+-Sn4+ cosubstitution?
The cosubstitution of Ca2+ and Sn4+ for Y3+ and Ga3+ alters the crystal field strength and local symmetry around Cr3+ in the octahedral sites. This modulation increases the nephelauxetic effect and reduces the crystal field splitting, shifting the emission from the 2E→4A2 (sharp line) to the 4T2→4A2 (broadband) transition, thereby enabling tunable NIR emission.
How does the optimized phosphor achieve an EQE of 34.96% and what is the role of Jahn-Teller distortion?
The EQE improvement is attributed to enhanced radiative transitions due to octahedral Jahn-Teller distortion, which increases the oscillator strength of the 4T2→4A2 transition. This distortion is induced by the size mismatch between Ca2+ and Y3+ and Sn4+ and Ga3+, leading to a more asymmetric local environment that favors radiative recombination.
What are the thermal quenching mechanisms and how does the phosphor retain 91.3% intensity at 423 K?
Thermal stability is governed by electron-phonon coupling (EPC) and oxygen vacancy (OV) defects. Weak EPC reduces non-radiative transitions, while OV defects can trap electrons and suppress thermal ionization. The combination of these factors minimizes thermal quenching, maintaining high emission intensity at elevated temperatures.
How does the NIR pc-LED device perform in terms of electroluminescence efficiency and long-term stability?
The device achieves an electroluminescence efficiency of 18.8% at 100 mA, which is competitive for plant lighting applications. Long-term stability is excellent, with less than 5% intensity loss after 30 days of continuous operation, indicating robust packaging and material durability.
What is the practical significance of the emission range (708–768 nm) for plant lighting?
This range overlaps with the absorption of far-red photosensitive pigments (Pfr), which regulate flowering and photomorphogenesis. By tuning the emission peak within this range, the phosphor can be optimized for specific plant species and growth stages, enhancing photosynthetic efficiency and crop yield.
Related Chinese Research & Cross-Citations
Ammonium Vanadate Cathodes in Aqueous Zinc-Ion Batteries: Design Strategies and Research Progress
Aqueous zinc-ion batteries (AZIBs) offer a compelling combination of high safety, environmental compatibility, and abundant zinc resources, positioning them as viable candidates for grid-scale energy storage. Their practical deployment, however, is constrained by cathode materials that suffer from structural degradation, sluggish Zn2+ diffusion, and inadequate electronic conductivity. Ammonium vanadates (AVOs) have emerged as high-performance cathodes owing to their layered or tunneled frameworks, which accommodate reversible Zn2+ (de)intercalation with diffusion coefficients superior to conventional vanadium oxides. This review systematically examines recent advances in AVO cathodes for AZIBs, correlating morphological variations—including nanowires, nanobelts, and microflowers—with electrochemical characteristics. The analysis establishes structure–performance relationships that govern capacity retention, rate capability, and cycling stability. Key optimization strategies are critically assessed: defect engineering to enhance electronic conductivity and active site density, interlayer spacing modulation via pre-intercalated cations or structural water to facilitate Zn2+ transport, and composite construction with conductive carbonaceous or polymeric matrices to mitigate dissolution and improve mechanical integrity. Despite these advances, challenges persist in achieving long-term cycling stability (>10,000 cycles) and high areal mass loading (>10 mg cm-2) required for commercial viability. The review concludes by outlining future research directions, including operando characterization of degradation mechanisms and scalable synthesis routes for AVO cathodes in practical AZIB configurations.
Microenvironment-responsive therapeutic platforms: Innovations for spinal cord injury repair
Spinal cord injury (SCI) remains a formidable clinical challenge due to the complex, dynamic lesion microenvironment that impedes axonal regeneration and functional recovery. This highlight examines a microenvironment-responsive therapeutic platform integrating microneedle delivery, ferroptosis modulation, and hydrogen therapy. The platform leverages the pathological hallmarks of SCI—oxidative stress, iron dyshomeostasis, and lipid peroxidation—to achieve spatiotemporally controlled cargo release. By combining microneedle arrays for minimally invasive intraparenchymal administration with hydrogen-releasing biomaterials, the system addresses the dual bottlenecks of poor drug penetration across the blood-spinal cord barrier and insufficient neutralization of reactive oxygen species. Ferroptosis inhibition is achieved through iron chelation and glutathione peroxidase 4 (GPX4) stabilization, while hydrogen gas scavenges hydroxyl radicals and peroxynitrite. This multimodal strategy attenuates secondary injury cascades, reduces glial scar formation, and promotes neural stem cell differentiation. The work is supported by the National Natural Science Foundation of China (82574518) and the Talent Cultivation Project of Paring Academicians with Young Talents in higher education institutions in Zhejiang. The authors declare no conflict of interest. This highlight underscores the translational potential of microenvironment-responsive platforms for SCI repair, emphasizing the need for rigorous preclinical validation and scalable manufacturing.
Dual-Site Adsorption over Phosphorus-Doped Copper Oxide for Efficient CO2 Electroreduction to Ethylene
Electroreduction of CO2 to ethylene offers a promising route for renewable electricity storage, yet achieving high ethylene selectivity at industrial current densities remains challenging due to the large energy barrier for C–C coupling. Here, we report a “MOF-assisted in situ doping” strategy to introduce the oxophilic nonmetal phosphorus (P) into the copper oxide (CuO) lattice, constructing a localized Cu–P dual-site adsorption configuration for the key *OCCHO intermediate. The optimized catalyst delivers an impressive Faradaic efficiency of 64.6% for ethylene with a partial current density of 646 mA cm-2. Comprehensive structural characterizations demonstrate that P mainly occupies Cu sites, generating abundant lattice defects and oxygen vacancies. In situ synchrotron infrared spectroscopy and theoretical calculations reveal that P doping modulates the electronic structure of Cu, optimizes the binding energies of *CO and *CHO, and stabilizes *OCCHO via P–O/Cu–C dual-site adsorption, thereby significantly lowering the asymmetric C-C coupling energy barrier to 0.74 eV. This work highlights a dual-site microenvironment regulation strategy for CO2-to-ethylene electroreduction.
Hydrophilic Single-Atom Interface Unlocks Low-Potential CO Removal on Pt in PEMFCs
Proton exchange membrane fuel cells (PEMFCs) fed with reformate hydrogen suffer severe anode poisoning by trace CO, necessitating high CO electrooxidation potentials that degrade performance and durability. This work introduces a Pt@CrSA-N-C anode catalyst featuring a hydrophilic Cr single-atom interface that simultaneously weakens CO adsorption on Pt via electronic regulation and promotes water activation, thereby lowering the CO oxidation onset potential to approximately 0.13 V vs. RHE. The onset potential was determined by two independent methods: the first potential at which the background-corrected current exceeds 0 mA cm-2 during CO oxidation reaction tests in a three-electrode system, and the potential at which the forward scan current exceeds the N2 background current in CO-stripping voltammetry. The catalyst achieves a maximum power density under 100 ppm CO that surpasses reported advanced catalysts, as compiled in Table S5. Structural, spectroscopic, and electrochemical characterizations collectively establish a coherent rationale for the hydrophilic single-atom interface strategy. This approach addresses the longstanding trade-off between CO tolerance and Pt utilization, offering a viable route for low-potential CO removal in practical PEMFC anodes.
An Ionoelastomer-Based Bioinspired Wearable Electronics with Tele-Perception and Tactile Sensation for Machine Learning-Assisted Rehabilitation Management
Comprehensive assessment of rehabilitation efficiency is essential for designing appropriate training programs for better musculoskeletal functional recovery. Existing contact-receptor-dependent rehabilitation assessment systems mostly focus on assessing the restoration of muscle function by evaluating grip strength or joint flexion angle; however, parameters reflecting neuromuscular synergistic function are always overlooked. Herein, we develop an ionoelastomer-based soft artificial electroreceptor (SAER) that integrates tele-perception and tactile sensation to track the rehabilitation process, collecting signals related to approaching speed and grip strength sequentially. The SAER uses polyurethane ionoelastomer incorporated with quasi-solid conductive salt as the electric field receptor, and is integrated on a rehabilitation-training ball after assembly to establish an untethered detection device; this enables the remote capture of hand approaching parameter within a 9 cm range, followed by the quantification of grip strength when contacting and grasping. Furthermore, a data-driven assessment system is established by integrating machine learning, which accurately classifies rehabilitation efficiency into six levels; it supports for rehabilitation evaluation and training programs adjustment. Overall, the SAER-based rehabilitation management system establishes a paradigm that synergistically evaluating parameters corresponding to neuromuscular functional restoration and holds strong potential for home-based active rehabilitation for minimizing dependence on frequent clinical supervision.
Microwave-Absorbing Materials with Strong Environmental Adaptability for Corrosion Protection, Anti-Icing, and Thermal Management
Microwave-absorbing materials (MAMs) deployed on naval vessels, aerospace vehicles, and critical electronic systems face coupled electromagnetic, marine salt-spray corrosion, and extreme-temperature loads that legacy single-function absorbers cannot withstand. This review consolidates progress on three environmentally adaptive MAM classes: corrosion-protective, anti-icing, and thermal-management absorbers. The electromagnetic loss and impedance-matching fundamentals are first established, then the synergistic mechanisms, design strategies, and characterization protocols for each class are examined against representative material systems and their measured performance. The analysis identifies a shared design logic—multiscale hierarchical architecture, interfacial polarization engineering, and multifunctional phase integration—while distinguishing the divergent protection mechanisms: barrier and passivation effects for corrosion, surface-energy and latent-heat regulation for anti-icing, and phonon–electron transport decoupling for thermal management. Persistent bottlenecks include the trade-off between impedance matching and protective-layer density, the absence of standardized coupled-field test protocols, and the scarcity of long-term salt-spray and thermal-cycling durability data. Future directions are delineated: intelligent self-adaptive absorbers, multiphysics-coupled simulation frameworks, and environmentally benign multifunctional integration. The review provides a theoretical and technical basis for the design, construction, and engineering scale-up of next-generation high-performance absorbers for aerospace, electronic, and marine equipment.