Advanced Optical Materials最新文献

Near-infrared mechanoluminescence (NIR ML) materials, owing to the unique force-to-light conversion characteristics, have attracted considerable attention, such as in bioimaging and structural health monitoring fields. However, current NIR ML materials are limited to a restricted selection of activators, which significantly hinders their practical applications. Herein, a series of Fe³⁺-activated double perovskite broadband emission NIR MLs are prepared (A₂BB'O₆:Fe³⁺). Among them, Sr₂ScSbO₆:Fe³⁺ has broadband NIR ML covering 800–1000 nm at a low activation threshold ≈1 N, while maintaining strong emission and reasonably stable cycling performance even at 573 K. Thermoluminescence measurements and density-functional-theory calculations identify the defect type and distribution of Sr₂ScSbO₆:Fe³⁺. The host exhibits a continuous distribution of shallow-to-deep defects (0.02–0.97 eV). These defects efficiently quench persistent luminescence and ambient-light interference, enabling a robust NIR ML noise-signal ratio. In addition, such NIR ML emission has bio tissue penetration ability, showing potential bio stress-related application imaging prospects.

The anti-ambipolar transistors based on van der Waals (vdW) heterojunctions, constructed from 2D materials, exhibit a variety of tunable physical properties, providing a versatile platform for the exploration of novel physical phenomena and the development of diverse electronic and optoelectronic device functions. Herein, this work presents MoS₂/Ta₂NiSe₅/WSe₂ vdW heterojunctions with significant antiambipolar characteristics, achieving a peak-to-valley ratio as high as 2.04 × 10³, attributed to the synergistic effect of gate modulation on the MoS₂/Ta₂NiSe₅ and Ta₂NiSe₅/WSe₂ vdW heterojunctions. The MoS₂/Ta₂NiSe₅/WSe₂ device implements a ternary inverter by the first Simulation Program with Integrated Circuit Emphasis model. The device also exhibits high-performance photodetection under 532 nm illumination via the photogating effect, with performance metrics including responsivity (R) of 342.5 A W⁻¹ and specific detectivity (D^*) of 9.17 × 10¹² cm Hz^1/2 W⁻¹. Additionally, the heterojunction with two built-in electric fields in the same direction via the photovoltaic effect can be used as self-powered photodetectors, with a R of 392 mA W⁻¹ and a D^* of 5.1 × 10¹² cm Hz^1/2 W⁻¹. And MoS₂/Ta₂NiSe₅/WSe₂ vdW photodetector is applied in the field of optical communication. This work not only achieves a multifunctional phototransistor with excellent electronic and optoelectronic performance but also demonstrates its significant potential in future “All-in-one” chip applications.

Lead sulfide (PbS) colloidal quantum dots (CQDs) have emerged as promising materials for near-infrared (NIR) and short wavelength infrared photodetection, owing to their cost-effectiveness in production, and broadband absorption extending up to 1550 nm. This spectral range provides significant advantages for applications such as autonomous driving. However, the performance of PbS CQD-based devices has been limited by their high leakage currents, especially under reverse bias, which limits detectivity and operational bandwidth. In this work, an innovative device architecture is proposed to substantially reduce dark current densities over a wide reverse bias voltage range. This approach integrates a multi-barrier structure with interlayered polymer charge-blocking layers within the CQD film, effectively suppressing leakage current and preventing breakdown under reverse bias. The CQD/polymer hybrid devices exhibit dark current densities as low as 2 × 10⁻⁵ mA cm⁻² under applied bias up to 5 V, and detectivity exceeding 6 × 10¹² Jones is consistently achieved between 3.5 and 6 V. This architecture also enables efficient field-assisted charge extraction, leading to enhanced bandwidth reaching 660 kHz, far surpassing conventional CQD-only devices. These results demonstrate a viable strategy to overcome the long-standing trade-off between detectivity and speed in NIR CQD photodetectors.

Chirality-induced spin selectivity (CISS) enables spin-polarized charge transport through chiral media without magnetic fields. While extensively studied in organic and biomolecular systems, CISS in semiconductors remains limited, lacking standardized methodologies and mechanistic understanding. II-VI and III-V semiconductor nanocrystals (NCs), with tunable band gaps, high optical quality, strong spin-orbit coupling (SOC) and diverse morphologies, provide an ideal platform for exploring spin-dependent phenomena. This review highlights fundamental concepts of chirality and its manifestation in nanostructures, distinguishing ligand-induced and intrinsic chirality in NCs. This work critically integrates recent advances on the microscopic link between chirality and spin selectivity, emphasizing mechanisms such as exciton-ligand hybridization, and surface/bulk inversion asymmetries that generate Rashba/Dresselhaus effects, leading to interfacial spin-filtering. This work describes structural control and chiroptical properties of chiral II-VI/III-V NCs, discussing factors like morphology, surface defects, and ligand chemistry, while outlining trade-offs among SOC, optical quality, and device integration. Mechanistic models, including exciton-ligand hybridization and photonic coupling, explain trends in circular dichroism. Strategies for tuning spin injection, transport, and relaxation are outlined, emphasizing SOC, structural anisotropy, and compositional engineering. This work assesses challenges in integrating chiral NCs into practical devices – including stability, scalability, environmental safety – and highlight opportunities in spin-LEDs, quantum computation, biosensing, and memory devices.

The design, fabrication, and comprehensive characterization of hole-doped Ge-rich SiGe parabolic quantum wells engineered to exhibit intersubband transitions in the mid-infrared spectral range around 120 meV are reported. The heterostructures are grown on Si substrates by low-energy plasma-enhanced chemical vapor deposition, enabling finely controlled compositional profiles and high crystalline quality. Thorough structural analysis confirms the formation of parabolic potential wells despite the presence of entropic interdiffusion. Photoreflectance spectroscopy is employed to investigate interband optical transitions in these heterostructures, whereas intersubband transitions are studied by Fourier-transform infrared spectroscopy that revealed characteristic constant-energy TM-polarized absorption features up to room temperature. At higher doping levels, a more structured spectral response is observed due to valence-band non-parabolicity. Tight-binding band structure simulations, incorporating many-body effects, accurately reproduce the observed spectral features. These results highlight the potential of SiGe parabolic quantum wells as a versatile and scalable platform for the development of Si-compatible mid-infrared optoelectronic devices based on intersubband transitions.

This work presents the synthesis, characterization, and functional evaluation of a new luminescent manganese(II) hybrid halide, (pr-ted)₂[MnBr₄], containing the organic cation (pr-ted)⁺ (1-propyl-1,4-diazabicyclo[2.2.2]octane). The compound exhibits green photoluminescence and undergoes a reversible transformation to a red-emitting hydrated form, (pr-ted)₂[MnBr₄(OH₂)], upon exposure to ambient humidity. Single-crystal X-ray diffraction reveals differences in coordination geometry between the two phases: a tetrahedral environment in the anhydrous form and a distorted trigonal bipyramidal in the hydrated phase. This structural change is responsible for the observed red shift in emission. The interconversion is fully reversible through thermal treatment or vacuum exposure. Photoluminescence and density functional theory calculations are employed to investigate optical behavior and electronic transitions. In situ X-ray powder diffraction confirms the humidity-induced phase transition. Both forms exhibit solubility in polar solvents, enabling the fabrication of luminescent coatings via wet-processing methods. Impregnation and nebulization approaches are explored. The impregnation process enables the fabrication of composites on porous materials, while the nebulization method produces homogeneous coatings on non-porous substrates. These coatings maintain reversible luminescent switching, validating the potential of (pr-ted)₂[MnBr₄] as a responsive material for humidity sensing. The integration of humidity-sensitive luminescent compounds into functional platforms using cost-effective techniques is demonstrated, for applications in environmental monitoring.

Light-matter strong coupling generates polariton states, which not only are the subject of fundamental physics studies but may also enable transformative technologies in lasing, optical switching, and chemistry. The exciton polaritons of semiconductors and molecules have been extensively studied. Here, we study the strong light-matter interaction of magic-size nanoclusters (MSCs), which can be considered as extremely confined nanocrystals that bridge the gap between semiconductors and small molecules. It is found that Cd₃P₂ MSCs, with superior size monodispersity and large oscillator strength, enable room-temperature strong coupling in a tunable Fabry–Pérot microcavity, with the Rabi splitting reaching 160 meV. Importantly, the derived transition dipole moment of Cd₃P₂ MSCs is consistent with that obtained from optical Stark effect measurements. The four orders-of-magnitude difference in electric field strength, however, highlights the essence of collective strong coupling in a microcavity in comparison to coupling with the light field in laser pulses.

0D organic-inorganic metal halides (OIMHs) with excitation-wavelength-dependent emissions have emerged as ideal materials for multiplexed anti-counterfeiting and information encryption. However, exploring multiple fluorescence/phosphorescence emissions stemming from distinct active centers within OIMHs remains challenging. Here, a phosphonium salt, [BCDBP]Br (BCDBP = butyldicyclohexyl(2′,6′-dimethoxy-[1,1′-biphenyl]-2-yl)phosphonium), which exhibits room-temperature phosphorescence (RTP) and anti-Kasha emission, is synthesized. This phosphonium salt is successfully employed to prepare a series of 0D OIMHs [BCDBP]₂Zn_1−xMn_xBr₄. The [BCDBP]₂ZnBr₄ preserves RTP and anti-Kasha behavior originating from the organic unit [BCDBP]⁺ while simultaneously achieving self-trapped exciton (STE) emission from [ZnBr₄]²⁻. Further analyses confirmed that the incorporation of [ZnBr₄]²⁻ also suppresses non-radiative decay, boosting the PLQY and extending phosphorescence lifetime. Furthermore, Mn²⁺ doping introduces [MnBr₄]²⁻ emission centers, enabling [BCDBP]₂Zn_0.998Mn_0.002Br₄ to exhibit rich excitation-wavelength-dependent emission from three distinct emissive centers: [BCDBP]⁺, [ZnBr₄]²⁻, and [MnBr₄]²⁻. This work successfully integrates an organic unit exhibiting anti-Kasha emission with two distinct inorganic emissive centers into a single material platform, where all components remain optically active and selectively addressable under specific excitation conditions. The strategy of assembling multimodal emissions within a single material demonstrates exceptional potential for advanced optical encryption and anti-counterfeiting applications.

Plasmonic resonances offer a powerful way for confining light and amplify interactions at materials interfaces. Among them, Tamm plasmons that arise at the interface between a metal film and a photonic crystal are particularly attractive because they can be excited at normal incidence and support strong field localization. In the specific case of porous or corrugated metal layers, the resonance field can extend to the metal/air interface, where it becomes accessible to overlying materials. Here, a Tamm plasmon device (TD) is introduced fabricated by depositing a corrugated silver layer on a SiO₂/TiO₂ mesoporous distributed Bragg reflector, and tuned to support a Tamm plasmon resonance at 575 nm to enhance light–matter interaction at the bioelectronic interface to maximize cell photostimulation. The TD enhances polymer absorption, influences emission and photothermal response. When interfaced with living cells, this translates into efficient light-driven depolarization at reduced excitation intensity. By concentrating evanescent fields at the polymer interface and acting as an asymmetrical open resonant cavity, the TD architecture markedly lowers the optical energy threshold for cell photostimulation. This versatile platform offers new opportunities for low-power photothermal therapies, neuromodulation, and advanced optoelectronic applications.

Hybridized local and charge transfer (HLCT) emitters are gaining attention as a promising class of high-efficiency emitters for organic light-emitting diodes (OLEDs) due to their efficient hot-exciton utilization and tuneable emission properties. However, a comprehensive understanding of the excited-state dynamics remains limited. To replenish this lacuna, three donor-π-acceptor (D-π-A) molecules having moderate twist angles (θ), with acronyms, TSBP, TBPS, and 2TBPS, comprising a triphenylamine (TPA) donor and a thiophene-modified benzophenone acceptor, are designed. These emitters exhibit high photoluminescence quantum yields (PLQYs) in solution and solid states, with TSBP achieving an exceptionally high PLQY of 94% in toluene, 40% in neat film, and 85% in polymethyl methacrylate (PMMA) film. Solvent-dependent photophysics, femtosecond transient absorption spectroscopy and theoretical investigations confirm the formation of the HLCT states in low and moderately polar environment. Utilizing a simple solution-processable method, OLED devices are fabricated with emitters exhibiting green and cyan-blue emission in non-doped and doped conditions respectively. Among them, TSBP delivers an outstanding device performance, achieving an external quantum efficiency (EQE_max) of 4.1% in a non-doped device (CIE: 0.28, 0.62) and a higher EQE_max of 5.6% (CIE: 0.20, 0.55) (CIE = Commission Internationale de l'Éclairage) in a CBP-doped device. These findings underscore the potential of HLCT-based emitters for developing efficient and cost-effective OLEDs.