Advanced Optical Materials最新文献

Low-dimensional metal halides have emerged as promising anti-counterfeiting materials. However, achieving a multi-mode and multi-color anti-counterfeiting system in metal halides remains challenging. In this study, copper-halide (TBP)₂Cu₄Br₆ (TBP⁺ = C₁₆H₃₆P⁺) single crystals are synthesized using a cooling crystallization method, which exhibits efficient dual-band emissions (542 and 708 nm), large Stokes shifts (282 and 330 nm), and a high photoluminescence quantum yield (PLQY) of 92.7% for 542 nm. These exceptional properties are attributed to the unique 0D structure of (TBP)₂Cu₄Br₆ single crystals, which facilitates the formation of two different self-trapped excitons (STEs). Furthermore, based on (TBP)₂Cu₄Br₆, a multi-mode and multi-color digital anti-counterfeiting system integrated is designed with Morse code information encryption, demonstrating promising applications in information security and anti-counterfeiting. This work not only illustrates an emitter in copper halides but also paves the way for achieving multi-mode and multi-color anti-counterfeiting systems.

2D materials offering ultrafast photoresponse suffer from low intrinsic absorbance, especially in the mid-infrared wavelength range. Challenges in 2d material doping further complicate the creation of light-sensitive p − n junctions. Here, a graphene-based infrared detector is experimentally demonstrated with simultaneously enhanced absorption and strong structural asymmetry enabling zero-bias photocurrent. A key element for those properties is an asymmetric singular metasurface (ASMS) atop graphene with keen metal wedges providing singular enhancement of local absorbance. The ASMS geometry predefines extra device functionalities. The structures with connected metallic wedges demonstrate polarization ratios up to 200 in a broad range of carrier densities at a wavelength of 8.6 µm. The structures with isolated wedges display gate-controlled switching between polarization-discerning and polarization-stable photoresponse, a highly desirable yet scarce property for polarized imaging.

Scintillating materials have advanced significantly with scientific and technological progress. However, developing scintillators capable of time-lapse imaging under extreme conditions, such as high-temperature environments, remains a formidable challenge. Herein, Tb³⁺-doped oxyfluoride glass ceramics (GCs) with exceptional scintillation performance and X-ray-induced persistent luminescence (PersL) are successfully fabricated. Remarkably, the luminescent intensities under ultraviolet and X-ray excitation are significantly enhanced by optimizing the Al₂O₃ content and inducing the precipitation of Na₅Lu₉F₃₂ nanocrystals. The integral X-ray-excited luminescence intensity reaches 219.3% of that of Bi₄Ge₃O₁₂. The GCs exhibit robust irradiation resistance even under high-power X-ray exposure. Real-time imaging based on GCs demonstrates a spatial resolution of 18 lp mm⁻¹. Furthermore, the GCs display pronounced thermally stimulated PersL following X-ray excitation, attributed to the generation of Frenkel defects. This behavior facilitates the development of a time-lapse imaging technique with high-temperature visibility after X-ray irradiation, achieving an impressive spatial resolution of 14 lp mm⁻¹, and allowing X-ray image storage for over 168 h. These findings underscore the immense potential of GC scintillators for advanced X-ray imaging applications, particularly in harsh environments.

In the modern era, structural color materials are regarded as safe and promising alternatives to colorants that contain harmful components. However, developing structural color materials that exhibit vivid colors with minimal angular dependence is crucial for their practical application. In this study, spherical colloidal crystals (photonic balls) with bright colors and effectively suppressed angular dependence are developed using monodisperse high refractive index CeO₂ particles. To fabricate these photonic balls, CeO₂@PDA particles are synthesized by coating CeO₂ particles with polydopamine (PDA), a black component. The light-absorbing PDA coating on each particle uniformly reduces the multiple scattering of light to form a black background, allowing the CeO₂@PDA photonic balls to exhibit brilliant structural colors. Compared to SiO₂ particles photonic balls, which are widely studied in previous research, CeO₂@PDA photonic balls have a significantly reduced angular dependence of structural color hue due to their composition of materials with a higher refractive index. Additionally, the CeO₂@PDA photonic balls are heat-treated in a nitrogen atmosphere, transforming the polymer component on the particle surface into a black carbonaceous material with a higher refractive index. This process further reduces the angular dependence of structure color hues observed from the photonic balls and improves color vibrancy.

In recent years, organic room-temperature phosphorescence (RTP) materials have garnered significant research interest. However, the design and synthesis of novel polymeric RTP systems continue to pose substantial challenges. By leveraging cyclotriphosphazene functionalization, four novel phosphors are successfully developed. The presence of numerous heteroatoms (O, N, P) within this structure significantly enhances molecular spin-orbit coupling (SOC). Initially, the incorporation of these novel phosphors into a polyvinyl alcohol (PVA) matrix yielded only weak RTP emissions. Remarkably, thermal annealing transformed these materials into long-lived cross-linked polymer RTP films. Specifically, a representative luminescent film (THMD@PVA) exhibits enhancements in phosphorescence intensity, lifetime, afterglow brightness, and quantum yield by factors of 8, 4, 18, and 6, respectively. With superior mechanical and luminescence properties, these RTP materials are well-suited for creating flexible and reconfigurable 3D objects. Furthermore, the dual luminescence of fluorescent and phosphorescent emissions expands their applicability, including fingerprint recording, thereby broadening the application scope of organic RTP materials.

Breast cancer remains the second most common cause of cancer-related deaths in women worldwide, with ≈70% of cases linked to the overexpression of Estrogen Receptor (ERα). Existing imaging tools often fail to reliably differentiate between ER-positive and ER-negative cancer cells. To address this limitation, two novel fluorescent probes, E2N and E2R, are synthesized by conjugating estradiol to styryl and rhodamine-based fluorophores using click chemistry. These probes are characterized by their photophysical properties, biocompatibility, and selective targeting of ER-positive cells. Cellular uptake studies demonstrate preferential internalization of E2N and E2R in ER-positive MCF-7, ZR-75-1, and T-47D cells, with minimal uptake in ER-negative MDA-MB-231, MDA-MB-468, and healthy COS-7 and NIH-3T3 cell lines. Kinetic studies reveal efficient and rapid uptake of E2N in ER-positive MCF-7 cells, while mechanistic investigations identified clathrin-mediated endocytosis as the receptor-mediated pathway for both probes. Localization studies further confirm their mitochondrial specificity in ER-positive cells, with E2R displaying higher mitochondrial selectivity. These findings underscore the potential of E2N and E2R as powerful tools for distinguishing ER-positive from ER-negative breast cancer cells. Their receptor-mediated targeting and precise imaging capabilities make them promising candidates for advancing breast cancer diagnostics and enabling more targeted therapeutic strategies.

Microspheres dispersed in composites exhibit excellent infrared emissivity for radiative cooling applications, which reflect sunlight and passively dissipate heat into space without electricity. In this study, hierarchical microspheres (HMs) with a two-tier structure, composed of SiO₂, TiO₂-coated SiO₂, BaSO₄, or PNIPAM, are incorporated into PDMS-based composites. These microspheres feature larger spheres assembled from submicrometer-scale nanoparticles and are fabricated via microfluidics to enhance radiative cooling performance. SiO₂ HMs not only boost visible light reflection and exhibit structural color through a photonic stop band but also achieve an average emissivity of 97.55% in the atmospheric window. Both experimental and simulated results show that HMs enhance the emissivity performance of the composite material compared with solid SiO₂ microspheres of the same diameter. Additionally, applying TiO₂ coating to SiO₂ HMs further increases the overall emissivity to 98.05%. Incorporating BaSO₄ HMs also increased the average visible reflectivity to 96.56%, while maintaining superior infrared emissivity at 97.58%. The inclusion of PNIPAM spheres enabled temperature-responsive transmissivity, with the composite materials containing PNIPAM and SiO₂ HMs preserving high infrared emissivity in the atmospheric window. These HM structures exhibit excellent solar reflectivity and thermal emission, making them effective for radiative cooling.

Lead halide perovskites (LHPs) have attracted significant attention for their exceptional optoelectronic properties, positioning them as prime candidates for next-generation electronics such as photodetectors (PDs), lasers, light-emitting diodes (LEDs), and memristors. However, integrating these materials into device architectures with CMOS-compatible technologies in a simple manner remains a critical challenge. This study introduces a universal method leveraging standard lithographic patterning to fabricate high-performance LHP PDs for red (R), green (G), and blue (B) color detection separately. Through optimization of the device stack and etching conditions, perovskite PDs are pixelated using a one-step lithography and pulsed argon (Ar) milling process. The resulting devices exhibit typical perovskite PD responsivity (0.3 A W⁻¹), low dark current density (less than 10⁻⁶ mA cm⁻²), high detectivity (over 10¹³ Jones), and short fall time (sub-20 ns without bias). This approach not only enhances device performance but also paves the way for scalable production of perovskite-based optoelectronic devices. The versatility and effectiveness of this method highlight its potential for broad applicability in CMOS-compatible perovskite-based image sensor technology.

A series of benzothiadiazole (BT)-based dichroic dyes with donor–acceptor–donor (D–A–D) molecular frameworks is designed and synthesized, exhibiting absorption spectra that cover the visible light region and are tunable through molecular modifications. Most of the newly synthesized dyes show high dichroic ratios and order parameters, ensuring strong optical anisotropy and good alignment within the liquid crystal host mixture. The performance of individual dyes in smart window applications is evaluated, with transmittance changes observed under dynamic electric fields, demonstrating their potential for use in electrically tunable smart windows. To achieve full visible-light modulation, the combination of complementary absorption dyes is screened and an optimized mixture Mix-7 is obtained, which not only achieves full visible-light absorption coverage but also demonstrates smooth and dynamic transmittance modulation under varying voltages. Finally, a prototype smart window filled with Mix-7 is fabricated to validate the continuous tunability of dye-doped liquid crystal-based systems. Additionally, further introduction of a polarizer film significantly reduces the transmittance of the demo, especially in the OFF state which presents an almost completely dark state, highlighting the potential for automotive smart window applications.

The surface ligands of perovskite quantum dots (PQDs) with colloidal properties are critical determinants of quantum efficiency, stability, and surface passivation. However, perovskite structures are sensitive to water and humid environments, which leads to decomposition, and they decisively limit stability through surface ligand and structure control. Herein, an approach using 3-mercaptopropyltrimethoxysilane (MPTMS) among silane materials with the advantages of chemical stability and nontoxicity is proposed. The excellent structural properties of MPTMS are confirmed by the interaction of the Pb-S, which formed an interparticle network through the reaction of the methoxy group bonded to Si. Additionally, fabricated PQDs indicate superior optical performance by suppressing the approach to moisture and acetone solvents. Particularly, silane passivation of the particles conferred hydrophobicity, as confirmed via contact angle and surface energy analysis. Furthermore, silane networks are formed through the MPTMS ligand exchange strategy, suggesting that PQDs are a facile platform for maintaining high quality in aqueous environments.