Silicon quantum dots (SiQDs) are an emerging class of high-performing, sustainable, environmentally safe luminescent nanomaterial. They offer opportunities for next-generation displays, solid-state lighting, medical applications, and quantum technologies. Here, we highlight recent breakthroughs in colloidal SiQD synthesis and photophysics, comparing eight synthetic strategies. Among these, we focus on the hydrogen silsesquioxane (HSQ) polymer route, a simple and cost-effective hot-injection-free method that yields highly crystalline, ultrabright, and stable SiQDs with photoluminescence quantum yields approaching 80%. We also describe how solvent engineering realizes SiQD light-emitting diodes (LEDs) with record external quantum efficiencies (EQEs, >16%), >700-fold-increased lifetimes, and far-red emissions to rival state-of-the-art perovskite QD LEDs. Moreover, rice husk-derived SiQD LEDs illustrate the potential for low-waste circular material cycles. Thus, SiQDs are a sustainable platform for plant growth technologies, photodynamic therapy, and beyond.

Blue light-excited zero-thermal-quenching near-infrared garnet CaY2Sc2Al2SiO12:Cr3+/Yb3+ phosphors for pc-LED application.

Abstract Recent advances in photovoltaic (PV) research have highlighted the critical function of the electron transport layer (ETL) in determining solar cell performance, as it governs electron extraction, hole blocking, and interfacial recombination. This work investigates the potential of tungsten trioxide (WO₃) as an ETL in chalcogenide perovskite (CP) solar cells through SCAPS-1D simulation. Two CP absorber materials, BaZrSe₃ and CaHfSe₃, were examined in combination with two benchmark ETLs, titanium dioxide (TiO₂) and tin dioxide (SnO₂), for comparison. The first analysis assessed the influence of ETL type on key PV parameters. Based on the ETL thickness of 100 nm and absorber thickness of 600 nm, SnO₂ consistently yielded the highest power conversion efficiencies (PCEs), while TiO₂ produced the lowest across both absorbers. From the simulated external quantum efficiency (EQE) and current-voltage (J-V) responses, WO₃ demonstrated promising potential despite slightly lower efficiencies than SnO₂. Under identical structural conditions, BaZrSe₃:WO₃ achieved a simulated PCE of 17.70%, whereas CaHfSe₃:WO₃ reached 14.85%, representing 5.9% and 4.8% reductions relative to their respective SnO₂-based configurations. Additional analysis on the effect of ETL thickness confirmed that 100 nm is the optimal value, balancing carrier transport and optical losses. The influence of bulk defect density (Nₜ) showed that device performance degrades significantly when Nₜ ≥ 10¹⁵ cm⁻³, while maintaining Nₜ ≤ 10¹⁴ cm⁻³ ensures higher efficiency. Similarly, interface defect density (Nᵢₙₜ) studies indicated that values below 10¹⁴ cm⁻² are necessary to suppress recombination losses at the absorber/ETL interface. Parasitic resistance analysis showed that higher Rs and lower Rsh mainly limit FF and PCE, underscoring the importance of minimizing resistive losses. To benchmark the present findings, comparisons were made with previous studies, which show that WO₃ delivers acceptable performance relative to other ETL materials, thereby reinforcing the reliability of the current simulation approach. These results underscore the importance of material compatibility and energy-band alignment in optimizing CP solar cell performance. Overall, WO₃ emerges as a viable ETL candidate with strong potential for future development of stable, lead-free, high efficiency CP solar cells.

Unlocking novel halogen germanate phosphors for full-spectrum lighting and ultra-sensitive temperature sensing.

Luminescence enhancement and thermal stability of alkali co-doped Eu3+:LaMgB5O10 phosphors.

Design of an integrated model using deep reinforcement learning and Variational Autoencoders for enhanced quantum security.

Analysis of external quantum efficiency measurements of degraded solar cells embedded in solar modules

Multifunctional groups improved photoluminescence efficiency of hot exciton materials for blue OLEDs with a maximum external quantum efficiency exceeding 12 %

Temperature depended IV-curve method for determining LED internal quantum efficiency

Reproductive stage-dependent heat stress responses from perspectives of photosynthesis, yield, and grain composition in contrasting Lupinus angustifolius varieties.

Abstract Quasi‐2D metal halide perovskites have emerged as a promising material for photodetection due to excellent optoelectronic properties, simple synthesis, and robust stability. Albeit, developing high‐performance photodetectors based on low‐dimensional quasi‐2D metal halide perovskite nanoparticles remains challenging due to quantum and dielectric confinement effects. Several approaches are employed to improve efficiency, with plasmonic nanostructures being among the most effective ones. Here, enhanced photodetection of quasi‐2D perovskite nanostripes are demonstrated resulting from the incorporation of octadecanethiol (ODT)‐functionalized Ag nanostructure arrays (ANA). Using colloidal lithography, ANA are fabricated. Reflectance spectroscopy and finite element method (FEM) simulations show that ANA supports localized surface plasmon resonance (LSPR) modes that spectrally coincide with the absorption and emission band of the perovskite. This spectral overlap enables interesting coupling interactions between the excitons and plasmons. The ODT‐functionalized ANA photodetectors exhibit weak to intermediate coupling facilitating resonant energy transfer, resulting in a photocurrent enhancement factor of 838 %. They achieve photoresponsivities of up to 70.41 mA W −1 , detectivities of 1.48 × 1011 Jones and external quantum efficiencies of 21.55%, which are approximately ten times higher than those of the reference photodetector. This study proposes a strategy to optimize plasmon‐exciton coupling and resonant energy transfer for high‐performance plasmonic‐perovskite photodetectors.

ABSTRACT In response to pressing environmental priorities, the development of nontoxic and stable alternatives to lead‐based Perovskite solar cells is critical. This study focuses on Cs 2 AuScI 6 , a lead‐free Perovskite, as a promising photovoltaic material. Through density functional theory (DFT) calculations using Wien2k, a bandgap of 1.30 eV is revealed, with Au‐ d and Sc‐ d orbitals playing key roles in electronic properties and Au atoms dominating charge distribution. The material exhibits visible absorption peaks of the 10 5 order, indicating its potential for solar applications. Conducted by DFT, 36 configurations combining various electron transport layers and hole transport layers (HTLs) are investigated. Copper Barium Tin Sulfide (CBTS) is identified as the optimal HTL due to its alignment with the absorber material. Five standout device architectures of ITO/WS 2 /Cs 2 AuScI 6 /CBTS/Ni, ITO/ZnO/Cs 2 AuScI 6 /CBTS/Ni, ITO/TiO 2 /Cs 2 AuScI 6 /CBTS/Ni, ITO/PCBM/Cs 2 AuScI 6 /CBTS/Ni, and ITO/IGZO/Cs 2 AuScI 6 /CBTS/Ni (Where ITO means Indium Tin Oxide) achieved exceptional power conversion efficiencies of 31.48%, 31.46%, 29.44%, 28.75%, and 31.82%, respectively, surpassing the 18.61% efficiency of the ITO/C 60 /Cs 2 AuScI 6 /CBTS/Ni structure. The study further examines practical performance factors, including resistances, temperature effects, current–voltage ( J – V ) characteristics, and quantum efficiency, thereby enhancing its real‐world applicability. These findings highlight the potential of Cs 2 AuScI 6 as a nontoxic, inorganic alternative for perovskite solar technology, contributing to the sustainable development of photovoltaics.

Abstract Achieving voltage‐invariant color stability in white organic light‐emitting diodes (WOLEDs) is a critical challenge hindering their practical application, especially in simplified, non‐doped architectures. In this work, a highly‐efficient, spectrally stable non‐doped WOLED is presented by incorporating an ultrathin interfacial barrier layer of CzSi at the emission interface. This functional layer effectively confines excitons and stabilizes the recombination zone by suppressing electron leakage and excessive hole injection, thereby achieving excellent charge balance. The optimized bi‐color device achieves a peak external quantum efficiency (EQE) of 18.8%, a current efficiency of 49.5 cd A −1 , and a maximum luminance exceeding 13,090 cd m − 2 . Remarkably, the device exhibits minimal chromaticity drift (ΔCIExy = 0.003, 0.009) across a wide voltage range (4–10 V). Exciton recombination profiling and single‐carrier transport measurements confirm that the CzSi layer functions as a bidirectional energy barrier, finely regulating charge recombination and spatial exciton distribution. Furthermore, this approach is extended to tri‐color WOLEDs, which exhibit a high color rendering index (CRI) of 89 while maintaining excellent voltage‐invariant emission. The dopant‐free, minimalistic design offers a practical and scalable pathway for the development of high‐performance WOLEDs with outstanding color stability and fidelity, paving the way for advanced display and solid‐state lighting applications.

ABSTRACT Solar‐driven H 2 production coupled with selective organic transformation represents a promising strategy for co‐generation of green hydrogen and high‐value chemicals, yet its feasibility relies critically on effective bifunctional photocatalysts. Herein, we report the synthesis of ultrafine Cd x Zn 1− x S nanocrystals derived from a zeolitic imidazolate framework (ZIF), featuring high surface area, shortened charge diffusion path, and enhanced H 2 evolution activity. Anchoring amorphous Pt sub‐nanoclusters onto these nanocrystals created a bifunctional catalyst (Pt‐Cd x Zn 1− x S) for efficient lactic acid photoreforming, enabling co‐production of H 2 with switchable selectivity toward pyruvic acid (PA) or 2,3‐dihydroxy‐2,3‐ dimethylsuccinic acid (DTA). The optimized 0.5Pt‐Cd 0.3 Zn 0.7 S catalyst achieved an exceptional H 2 production rate of 270.6 mmol h −1 g −1 , 73.1% PA selectivity, and 62.8% apparent quantum efficiency at 400 nm. Mechanistic studies revealed that lactic acid undergoes C‐H cleavage to form carbon‐centered radicals. Pt sub‐nanoclusters served as electron sinks to facilitate O‐H dissociation and PA formation, whereas pristine Cd 0.3 Zn 0.67 S promoted direct C‐C coupling of radicals to predominantly yield DTA. This work offers critical insights for designing advanced bifunctional photocatalysts to integrate solar hydrogen and value‐added chemical synthesis.

Abstract In this study, red-emitting Mn 4+ -activated CaAl 4 O 7 phosphors were successfully synthesized using a simple solid-state reaction method. The incorporation of Mn 4+ ions into the CaAl 4 O 7 lattice was confirmed by x-ray diffraction (XRD) analysis. The synthesized phosphors displayed a red emission band peaking at 656 nm, which can be tuned by adjusting the doping concentration and annealing temperature. The highest photoluminescence intensity was observed for the CaAl 4 O 7 :0.3%Mn 4+ sample annealed at 1500 °C. The optimized CaAl₄O₇:Mn 4+ phosphors exhibited a long lifetime of 0.827 ms, good color purity of 99.5% and high quantum efficiency of 49.7%. The plant growth LEDs were fabricated by combining the red-emitting optimized CaAl 4 O 7 :Mn 4+ phosphor with various LED chips emitting at 365, 395, 420, and 450 nm. The red phytochrome exhibits good alignment with the LED chips using UV and NUV excitation (around 365 nm and 395 nm), while chlorophyll A and B show strong correspondence with plant LED chips based on the violet (420 nm) and blue (450 nm) LED chips, respectively. Furthermore, high CRI warm white light-emitting diodes (W-WLEDs) were fabricated using the red-emitting CaAl 4 O 7 :Mn 4+ phosphor with a commercial yellow YAG:Ce 3+ and a 465 nm blue LED chip. Adding CaAl 4 O 7 :Mn 4+ significantly enhanced the CRI from 77 to 91, improved the R9 value from −15 to 84, and reduced the correlated color temperature from 5581 to 3998 K. The results indicate the significant potential of CaAl 4 O 7 :Mn 4+ phosphor for applications in both high CRI W-WLEDs and plant growth LEDs, effectively responding to red phytochrome and all chlorophyll absorption bands.

Solution-processable circularly polarized (CP) organic light-emitting diodes (OLEDs) are unique devices generating CP electroluminescence. However, the efficiency of solution-processed CP OLEDs is still low compared with vacuum-processed CP OLEDs. In this work, highly efficient and narrow-emitting solution-processed CP OLEDs are developed using a novel multi-resonance (MR) thermally activated delayed fluorescence (TADF) emitter operated by an intramolecular TADF sensitized MR-TADF emission mechanism. The CP-type MR-TADF emitter is designed to have a TADF antenna unit and a terminal MR-TADF unit connected through a planar chiral unit. The TADF antenna unit plays the role of initial exciton generator, harvesting both singlet and triplet excitons, and the exciton energy is transferred to the terminal MR-TADF unitby through-space energy transfer. As a result, the external quantum efficiency (EQE) of the chiral MR-TADF emitter is significantly enhanced from 16.2% of the MR-TADF emitter without the TADF antenna unit to 28.0% by solution process. The CP OLEDs showed an electroluminescence dissymmetry factor of 10-3 order, demonstrating that the molecular design is also effective to achieve highly efficient CP emission in OLED. This work establishes an effective strategy for realizing highly efficient narrowband CP electroluminescence via intramolecular TADF-sensitized MR emission.

Achieving deep-blue emission with high efficiency and color purity remains a major challenge for next-generation organic light-emitting diodes (OLEDs), particularly those targeting the BT.2020 color standard. Herein, a methyl substitution-induced molecular distortion strategy is proposed to construct deep-blue multi-resonance thermally activated delayed fluorescence emitters (BN-M2 and BN-M3), that simultaneously enhance spin-orbit coupling and suppress π-π stacking. Strategic methyl substitution induces significant distortion in the B/N core geometry (dihedral angle > 40°), boosting reverse intersystem crossing rates (up to 2.71 × 106 s-1) and mitigating aggregation-caused quenching. The optimized emitters achieve narrowband deep-blue emission (Commission Internationale de l'Éclairage y coordinate, CIEy = 0.045) and near-ultraviolet emission (CIEy = 0.035), with a full width at half maximum of 22-24nm and near-unity photoluminescence quantum yields (≈100%). Furthermore, OLEDs show record-high external quantum efficiency with minimal roll-off: BN-M3 achieves 34.8% for BT.2020 blue emission, while BN-M2 reaches 21.4% in the near-UV spectrum, setting a new benchmark. Notably, the device performance remains stable even at high doping concentrations (up to 15 wt%). This work provides a viable pathway toward realizing BT.2020-compliant blue OLEDs with both outstanding optoelectronic performance and excellent industrial processability.

All inkjet-printed, 200 pixels per-inch quantum-dot light-emitting diodes were fabricated with a photo-crosslinkable polymer as a hole transport layer (HTL) in this study. Inkjet printing of high-resolution multilayer devices faces significant challenges, such as accurate droplet deposition and interfacial mixing between layers. High-resolution pixel substrates demanded precise drop placement accuracy (<10µm) and ⩽ 4 pL droplet volumes; accordingly, binary and ternary solvent systems were adopted, and custom trapezoidal waveforms maintained stable jetting. Interfacial mixing during solution-based processes, leads to undesired intermixing between the HTL and emissive layer (EML), ultimately causing Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)] (TFB) erosion. To alleviate this issue, the crosslinkable polymer was introduced. The crosslinkable TFB was synthesized with 30 mol% azide-functionalized backbones to enable photo-crosslinking. Devices with pristine and crosslinkable TFBs (ITO/PEDOT:PSS/HTL/CdSe@ZnS/ZnO/LiF/Al) were compared; the latter exhibited approximately twofold improvement in external quantum efficiency (EQE) and clear pixel-scale electroluminescence (EL), while the former showed erosion artifacts. Film morphology and electronic properties were examined with Fourier-transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), and photoelectron spectroscopy in air (PESA). FT-IR confirmed efficient azide cross-linking. AFM and EL imaging revealed that CdSe@ZnS layers on pristine TFB fractured into pin-holed islands, whereas those on cross-linked TFB formed smooth, continuous, uniformly emissive films. PESA detected an ∼0.1 eV downward shift of the TFB highest occupied molecular orbital level, facilitating hole injection and confining exciton recombination to the EML. These combined chemical, morphological, and electronic improvements raised the EQE from 0.11% to 0.21%. Notably, this study demonstrates the first laboratory-scale realization of fully inkjet-printed multilayer QLEDs with pixelated substrates.

Organic open-shell emitters capable of near-infrared (NIR) emission are of growing interest for optoelectronic and bioimaging applications, yet achieving high efficiency remains a fundamental challenge due to severe nonradiative losses. Here, we report a rational design strategy that integrates intramolecular hydrogen bonding and rotational restriction to construct highly emissive NIR radicals. Incorporating a pyrimidine-modified tris(2,4,6-trichlorophenyl)methyl scaffold with donor units yields two radicals, Pm-DMNA and Pm-TPA, featuring planar donor-acceptor geometries and rigidified conformations. These structural features enhance charge-transfer interactions while effectively suppressing vibrational deactivation pathways. As a result, Pm-DMNA exhibits a photoluminescence quantum efficiency (PLQE) of 36% at 783 nm and enables organic light-emitting diodes (OLEDs) with a record-high external quantum efficiency (EQE) of 5.9% beyond 850 nm. This work illustrates a generalizable approach for engineering efficient open-shell emitters through precise conformational control.

Abstract We investigate the structural, energetic, and electronic properties of Sn-doped germanium nanowires (NWs) along [001] direction, with various diameters. The direct bandgap transition is explored by the tensile strain of GeSn alloy for emission near 0.8 eV in the third optical communication window. Our first-principles calculations show that the direct bandgap transformation can be achieved in GeSn NW-shell with uniaxial strain change. Drawing inspiration from the significant expansion of Ge volume, the 7.5–14.04% Sn is proposed to be doped into the GeSn alloy for a dramatic transition into a direct bandgap in NWs. The calculation demonstrates that the direct bandgap transition is determined not only by the doping contents of Sn atoms, but also by changing symmetry and distribution region of the Sn atomic in GeSn alloy, where the Sn concentration is needed to transform into direct bandgap increases with the larger diameter of NWs. According to these results, a physical model with three levels system for stimulated emission in the optical communication windows is built, in which the external quantum efficiency of emission is higher than 20%.