IrIII-AuI luminescent bimetallic complexes have drawn growing interest for applications in photonics, catalysis, and biomedicine. Here, we report the synthesis of a new photoluminescent IrIII-AuI complex, the [(ppz)2Ir(μ-bbip)AuBr]PF6, incorporating 1,3-dibenzyl-1H-imidazo[4,5-f][1,10]phenanthrolin-3-ium bromide (bbip) as a bridging N-heterocyclic carbene (NHC) ligand. Among the various characterizations employed, single-crystal X-ray diffraction (SC-XRD) confirmed the structure of the complex, validating the proposed molecular formulation and coordination sphere. For comparative purposes and under similar conditions, the monometallic IrIII complex [Ir(ppz)2(bbip)](PF6)2 was synthesized and also validated by SC-XRD. Both complexes showed broad UV-vis excitation and orange-to-red emission in all tested solvents. Notably, the IrIII-AuI complex exhibited lower solvent polarity sensitivity than the mono-IrIII analog, with AuI coordination to bbip causing a slight emission blue shift. The incorporation of AuI significantly enhanced the photoluminescent properties, doubling both, the emission lifetime (τ) from 278 to 554 ns and the quantum yield (Φ) from 25 to 61% in degassed DCM. Notably, Φ remained high (30%) even in air-equilibrated DCM.

Interfacial electric fields govern charge separation in van der Waals photodetectors, yet they are typically modulated by electrostatic gates or ferroelectric interlayers, which introduce power consumption and stability challenges. Here, we show that the twist angle intrinsically controls interfacial electrostatics in a low-symmetry ReS2/ReSe2 heterostructure. Rotating the anisotropic crystal axes reconstructs the interfacial polarization landscape, leading to a reversal of the built-in electric field in the orthostacking configuration. This enables efficient self-powered photodetection with an on/off ratio of 105 and a high responsivity. Twist-controlled electrostatic reconstruction further modulates carrier separation and anisotropic transport, transforming the polarization-dependent photocurrent from a two-lobed to an approximately four-lobed profile and enabling tunable polarization sensitivity. Moreover, the deterministic twist-angle-dependent photocurrent allows hardware-level encoding. These results establish twist engineering as an effective strategy for tailoring interfacial fields and multifunctional optoelectronic responses in low-symmetry van der Waals heterostructures.

Ferroelectric domain walls endow ferroelectric materials with sub-bandgap near-infrared (NIR) light absorption properties, holding broad prospects for the development of infrared visual synaptic functions. Their stable behavior in two-dimensional (2D) in-plane ferroelectric materials under external out-of-plane electric fields lays a material foundation for building 2D NIR visual synapses─additionally, the in-plane polarization characteristic further enables optical polarization-sensitive characteristics. Herein, we fabricate a multilayer graphene (Gr)/NbOCl2/Gr heterojunction using a wide-bandgap 2D in-plane ferroelectric material and exploit the NIR light absorption properties of ferroelectric domain walls to achieve NIR visual synaptic functions at ultralow voltage. We investigated the heterojunction's responses to external bias, pulse frequency, and pulse intensity in the 808 nm-2200 nm wavelength range, along with its paired-pulse facilitation/depression (PPF/PPD) and multipulse characteristics. Specifically, the heterojunction can implement synaptic functions at 1 mV, with a single-pulse energy consumption as low as 8.74 fJ, and achieves nearly symmetric PPF/PPD characteristics under positive/negative voltages. Notably, the heterojunction shows excellent optical polarization sensitivity, with a polarization ratio up to 9.12 under 1064 nm light illumination. This work offers key technical and theoretical support for advancing high-performance 2D NIR polarization-sensitive visual synapses and accelerates the application of ferroelectric domain wall materials in next-generation visual neuromorphic computing.

Multispectral compatible stealth is crucial for modern detection environments. Despite conflicts among stealth mechanisms, current strategies lack effective compatibility. This study introduces a flexible gradient metamaterial structure inspired by bionic design and machine learning's forward prediction mechanism. This structure achieves spectral decoupling and enhances stealth performance across infrared, radar, and visible light spectra. The multispectral compatible stealth metamaterials (MCSM) comprise a radar infrared compatible stealth layer (RICSL) with high transmittance (78.56%) and a pixelated tunable visible light camouflage pixel layer (VLCPL). By adjusting the hexagonal patches' filling rate on the infrared stealth layer (ISL), a blend of low infrared emissivity (0.2) and high microwave transmission efficiency is achieved. The structure ensures efficient microwave absorption through gradient impedance transition and multiscale loss mechanisms, with absorption efficiency exceeding 90% in the measured wideband range of 6.34 to 24.91 GHz, along with polarization insensitivity and angular stability. The VLCPL can adapt patterns to mimic jungle, ocean, and desert environments. In practical settings, these metamaterial structures demonstrate flexible adaptive features in infrared and visible light stealth effects, paving the way for innovative multispectral compatible stealth technologies.

Photodetectors that simultaneously integrate high responsivity, fast response, self-powered operation, and polarization sensitivity are highly needed for advanced imaging and optical information processing, yet remain challenging to realize in a simple device architecture. Here, the in-plane anisotropic ReSe2 and narrow-bandgap Ta2NiSe5 are utilized to construct a ReSe2/Ta2NiSe5 van der Waals heterojunction photodetector with self-powered broadband operation from 375 to 850 nm. Under 532 nm illumination in the self-powered mode, the device exhibits a responsivity of 0.381 A W-1 and a specific detectivity of 5.71 × 109 Jones. The device also presents a fast temporal response with rise and fall times of 44 and 70 μs, respectively, as well as a -3 dB bandwidth of approximately 5 kHz, demonstrating excellent weak light and high-speed detection capability. Moreover, under zero bias, the device exhibits photocurrent polarization ratios of 1.56 and 1.83 for the vertically stacked and laterally stacked configurations, respectively, indicating a clear polarization-sensitive photoresponse. Benefiting from these features, the device further enables real-time polarization-resolved imaging of specific patterns and reliable optoelectronic signal recognition. This work establishes a simple and effective strategy for the development of miniaturized, low-power, broadband photodetectors with intrinsic polarization sensitivity based on 2D van der Waals heterostructures.

This paper presents a bifunctional reconfigurable terahertz metamaterial device that integrates ultra-wideband absorption and high-efficiency broadband polarization conversion functionalities based on the phase-change material vanadium dioxide (VO2). By exploiting the reversible insulator-to-metal phase transition of VO2 near 68 °C, the device achieves dynamic switching between two distinct electromagnetic response mechanisms. When VO2 is in its insulating state, the device operates as a broadband linear cross-polarization converter. Upon transitioning to the metallic state, the device functions as an ultra-wideband perfect absorber. The physical mechanisms underlying the dual functionality are elucidated through surface current distribution analysis, electric field monitoring, impedance matching theory, and equivalent electromagnetic parameter extraction. Comprehensive parametric studies reveal the influence of key structural dimensions on device performance, while angular dependence analyses demonstrate excellent polarization insensitivity and wide-incidence-angle stability in both operational modes. Compared with recently reported terahertz devices, the proposed design exhibits superior bandwidth performance, compact structural dimensions, and dynamic functional reconfigurability, making it a promising candidate for applications in intelligent stealth systems, terahertz imaging, optical switching, and advanced communication technologies.

A single-layer, polarization-insensitive frequency-selective rasorber (FSR) with quad-band absorption performance is proposed. The presented FSR is developed by integrating a quad-band resonant absorber and a single bandpass frequency-selective surface (FSS) on opposite sides of an FR4 substrate. In the absorption bands, the top layer effectively absorbs electromagnetic waves, while the backside FSS functions as a reflector. In the transmission band, the top layer becomes nearly transparent, allowing efficient wave passage through the backside FSS. The combination of the two layers results in effective multi-functional performance. The top layer achieves over 90% absorption at 2.14, 2.88, 6.02, and 7.32GHz. The backside FSS generates a transmission band at 4.54GHz with low insertion loss. The design exhibits enhanced angular stability up to 50° for both TE and TM polarizations, with polarization insensitivity ensured through four-fold rotational symmetry. The physical mechanism is analyzed using an equivalent circuit model and effective-medium analysis. A 15 × 15 prototype has been fabricated and measured, showing excellent agreement with simulations. This resistor-free single-layer FSR is suitable for radar cross-section (RCS) reduction, electromagnetic interference (EMI) mitigation, and multi-functional radome applications in S- and C-bands.

Infrared polarization-sensitive visual synapses distinguish target details under background interference or low contrast, serving as the core for meeting critical fields' demand for efficient infrared optical information processing and recognition. Combining negative/positive photoelectric effects overcomes traditional single-polarity photoresponse limitations in simulating biological synapses' excitatory-inhibitory dual states, laying a crucial foundation for encoding complex neural signals and realizing brain-like multi-level information processing. Integrating wavelength-dependent positive/negative photoresponse switching with infrared polarization sensitivity is key to breaking through existing bottlenecks. Herein, we construct a two-dimensional heterojunction using anisotropic narrow-bandgap semiconductor PdSe2 and semi-metal NbSe2, successfully fabricating a visual synapse integrating the aforementioned two properties. Under 808/1064nm light illumination, asymmetric current synaptic pulse modulation is achieved via positive/negative voltage regulation, and positive/negative photoresponse switching is realized under low-voltage modulation. Under 808-2200nm light illumination, investigations on bias voltage, pulse frequency, and pulse intensity demonstrate that the heterojunction can implement synaptic functions at a low bias of 1mV, with a single-pulse energy consumption as low as 0.298 pJ. Notably, the heterojunction possesses excellent polarization sensitivity, achieving a polarization ratio of 12.67 under 1550nm light illumination. This work provides a highly promising platform for the development of high-performance multi-dimensional visual systems.

To overcome the limitations of intensity- or wavelength-based polarity sensing in cells, we developed a novel fluorophore utilizing steric hindrance to resist viscosity interference while maintaining high polarity sensitivity and PLQY. By combining intensity and wavelength of the probes, we achieved precise polarity analysis of specific organelles while eliminating interference of viscosity.

Polarization-sensitive photodetectors that simultaneously deliver self-powered operation, broadband response, and high polarization selectivity remain challenging due to intrinsic trade-offs between carrier separation efficiency and anisotropic photoresponse in low-symmetry materials. Here, we report a CuI/ReS2 van der Waals heterojunction photodetector that addresses these challenges through a synergistic approach based on interface-engineered built-in electric fields coupled with intrinsic in-plane anisotropy. The heterojunction enables efficient photocarrier separation, while the dark current is effectively suppressed, resulting in stable self-powered operation. Under 365 nm illumination at zero bias voltage, the photodetector exhibits an open-circuit voltage of -175 mV, a short-circuit current of 25 pA, and a responsivity of 8.02 mA/W. At a bias voltage of 1 V, the photodetector demonstrates broadband photodetection from 365 to 810 nm, with a peak responsivity of 590.59 mA/W, a detectivity of 6.18 × 1010 Jones, an on/off current ratio of 103, and rapid rise and decay times of 7.93 and 8.73 ms. Moreover, the CuI/ReS2 photodetector exhibits polarization sensitivity, achieving a polarization ratio of 2.84 at 660 nm. We demonstrate polarization-encoded imaging, highlighting the capability of the device for real-time optical information processing. This work demonstrates a feasible strategy for integrating self-powered operation, broadband detection, and polarization sensitivity, offering a promising platform for compact intelligent optoelectronic systems.

Stimuli-responsive molecular materials that show low-frequency (LF) terahertz (THz) responses are promising candidates for molecular switches and sensors in next-generation photonic technologies. In this work, we report two novel compounds, thermally activated spin-crossover (SCO) material {[Fe(pyridine)2][Hg(SCN)3]2}n (1) and paramagnetic {[Fe(pyridine)2][Hg(SCN)4]}n (2), obtained by selectively controlling the precursor ratios. Pressure-dependent crystallographic, magnetic and Raman spectroscopic studies confirm pressure-induced SCO from high-spin to low-spin Fe(II) at room temperature and ∼1 GPa of pressure. The Raman-active modes in both compounds display substantial blue shifts under compression, with maximum pressure sensitivities reaching 7.89 cm-1/GPa near 240 cm-1, and with the additional observation of a low-energy mode in 1 that shows an unusual red shift through the pressure-induced SCO. Angle-dependent Raman measurements in the LF, fingerprint and C≡N stretching regions of the spectrum also show strong polarization sensitivity. First-principles modeling of the IR- and Raman-active phonon modes in both ambient and high-pressure structures reliably reproduces the THz absorption and angle-dependent Raman spectra, allowing assignment of the spectral features to the underlying atomic motion. This work establishes pressure tuning of the LF phonon modes and spin states in molecular SCO materials as a novel approach to modulating THz light and hence provides new avenues for the design of tunable THz absorbers for advanced photonics applications.

Negation height and NPI licensing in Jordanian Arabic: Experimental support for an agree-based account

The gut-tumor metabolic axis: A comprehensive exploration of bidirectional crosstalk in cancer immunotherapy.

The growing demand for polarized photodetection has driven the need for compact, integrated, and multifunctional device architectures. Although one-dimensional (1D) materials are of significant interest for their innate polarization sensitivity among viable integration strategies, current research has largely overlooked the anisotropy induced by geometric dielectric confinement, remaining mainly focused on optoelectronic anisotropy from lattice symmetry breaking. To bridge the gap, here we investigate geometry-governed optoelectronic anisotropy in quasi-1D GaS nanoribbons with intrinsically isotropic atomic structures. Dielectric mismatch between the ribbon and its surroundings leads to a general polarization-dependent photoresponse during near-field scattering. Steady-state and transient spectroscopy further reveal that the dielectric confinement substantially modulates light absorption, phonon scattering, and carrier diffusion. Remarkably, this geometry-governed anisotropy exhibits sufficient strength and robustness to effectively support applications in areas such as polarized imaging, stress mapping, and visual cryptography. Our work provides fundamental insights into the optoelectronic anisotropy of 1D nanomaterials and offers a rational basis for exciting material properties and optimizing device designs in future polarized photonics.

This study introduces a reconfigurable terahertz metasurface that enables ultra-wideband absorption and cross-polarization conversion through the phase transition of vanadium dioxide (VO2). In the metallic phase, VO2 operates as a broadband absorber, attaining an impressive absorption efficiency with a relative bandwidth of up to 97.6% throughout the 3.25-9.45THz frequency range, while sustaining a high absorption rate across an incidence angle spectrum of 0°-60°. Upon VO2's transition to the insulating state, the device becomes a highly efficient polarization converter functioning within the 3.17-9.02THz range, consistently achieving a polarization conversion ratio (PCR) over 90% for both x- and y-polarized incident waves. This design guarantees ultra-wideband performance in both operational modes, exhibiting remarkable polarization insensitivity and wide-angle stability; additionally, the absorption efficiency may be continuously and dynamically adjusted based on the extent of VO2 phase transition. The engineered switchable device possesses extensive application potential in terahertz dynamic stealth, high-speed communication, and high-contrast polarization imaging.

Linear polarization-sensitive photodetectors play a pivotal role in enhancing optical signal acquisition and suppressing stray light, thereby facilitating improved target detection and identification in complex environments such as low-light conditions and haze. Emerging two-dimensional (2D) in-plane anisotropic materials offer significant advantages for simplifying optical systems owing to their facile integration onto complex architectures and superior photodetection capabilities. In this work, we report the fabrication of a linear polarization-sensitive photodetector based on a WSe2/SnS0.25Se0.75 van der Waals heterojunction. The electrical conductivity anisotropy between the armchair and zigzag directions in the WSe2/SnS0.25Se0.75 heterojunction can be dynamically tuned via gate modulation, with values ranging from less than 1 to as high as 257. Furthermore, polarization-dependent carrier transport measurements reveal a significant anisotropy in mobility with a ratio of μarmchair/μzigzag reaching 2.76. The fabricated device exhibits high polarization sensitivity and remarkable photoresponse performance along the armchair orientation, including a responsivity of 2.57 A/W, a detectivity of 5.76 × 1010 Jones, a rise/decay times of 2.86/2.24 ms, and a photocurrent anisotropic ratio of 7.8. These findings reveal the physical mechanisms in 2D anisotropic heterostructures and provide design principles for high-performance linear polarization-sensitive photodetectors.

To meet the demands of terahertz electromagnetic interference suppression and efficient energy absorption, this paper proposes a three-band terahertz metamaterial absorber based on an alumina substrate and vanadium dioxide thin film. Simulations show that in TE and TM modes, nearly perfect absorptions of 99.85% and 99.76% are achieved at 0.833 THz, with secondary absorption peaks at 0.626 THz and 0.874 THz (both >65%). The highly symmetric geometry ensures polarization insensitivity. Parametric studies reveal how bridge width and base side length affect the resonance mode. This design provides new ideas for electromagnetic shielding, energy harvesting, and high-sensitivity sensing in the terahertz band. Its lightweight, thin structure and multi-physics collaboration mechanism demonstrate potential for wearable devices and implantable medical applications. Future work will focus on experimental verification, dynamic frequency reconstruction, and adaptability to extreme environments .

Metasurfaces are confined to static functionalities and lack reconfigurability-a key characteristic urgently needed for their practical applications in dynamic environments. To address the critical challenges of traditional metasurfaces, including fixed functions, polarization dependence, bulky imaging systems, difficulties in integrating edge detection with bright-field imaging, and the requirement for additional digital post-processing, we propose to leverage the dynamic reconfigurability enabled by phase change materials, combining it with polarization insensitivity and omnidirectional dynamic switching between high-resolution edge extraction and clear bright-field imaging. In this paper, we propose a dual-polarization Laplacian differentiator operating in the terahertz band based on a nonlocal perforated metasurface, with dynamic function switching achieved by regulating the phase transition of vanadium dioxide (VO2). When VO2 is in the insulating state, the device can directly perform two-dimensional second-order image edge detection. When VO2 transitions to the metallic state, it switches to bright-field imaging mode. The Optical Transfer Function (OTF) required for Laplacian operations is achieved by exciting the Quasi-Bound States in the Continuum (Q-BIC) mode under p- and s-polarized terahertz wave illumination, which endows the device with an angular dispersive response matching the Laplacian operator's requirements. This differentiator offers dual-polarization-compatible edge detection, and its efficient, high-performance function switching-coupled with the benefits of dual-polarization imaging-provides robust technical support for terahertz-band applications including machine vision, biomedical detection, and image processing.

Abstract Abstract： The absorption–transmission–absorption–transmission (A-T-A-T) type Frequency Selective Rasorber (FSR), featuring dual absorption bands and dual transmission passbands, has attracted considerable attention for modern electromagnetic applications. However, most existing A-T-A-T FSR designs cannot simultaneously achieve a wide absorption bandwidth and low insertion loss, which limits their practical use in high-performance systems. To overcome this challenge, a polarization-insensitive and miniaturized A-T-A-T type FSR with wide absorption bandwidth and low insertion loss is proposed. The lossy layer consists of metallic patterns loaded with four resistors, which broadens the lower-frequency absorption band. The lossless layer is designed as a bandpass frequency selective surface incorporating a cross-shaped slot and four rectangular apertures, generating two transmission poles for dual-band transmission. The proposed structure operates over 3.59–18.6 GHz (135.29%), exhibiting two absorption bands of 3.59–13.7 GHz (116.95%) and 16.21–17.13 GHz (5.52%). In addition, two transmission passbands are obtained at 15.05 GHz and 18.6 GHz, with minimum insertion losses of 0.59 dB and 0.58 dB, respectively. Furthermore, the proposed design provides polarization insensitivity, stable performance under oblique incidence up to 45°, and compact dimensions with a thickness of 0.078λ and a unit-cell size of 0.014λ². To verify its practical feasibility, a 20 * 20 array prototype was fabricated and measured. The measured results agree well with the simulated ones, confirming the effectiveness and reliability of the proposed design. Owing to its balanced and comprehensive performance, the proposed A-T-A-T type FSR is a promising candidate for dual-band radiating system shielding, radar cross-section (RCS) reduction, and electromagnetic interference (EMI) suppression.

Low-dimensional materials with in-plane anisotropy are ideal candidates for polarization-sensitive photodetection. Based on the gate-tunable bipolar transport mechanism of field-effect transistors (FETs), by integrating anisotropic GeSe and MoS2 with high-NIR-absorptive PbSe, we fabricated a PbSe/GeSe/MoS2 dual-heterojunction photodetector featuring gate-tunable charge distribution. The device utilizes two distinct built-in electric fields; application of gate voltages enables precise control over interfacial charge accumulation, thereby modulating photocurrent polarity and polarization sensitivity. At zero bias, the device exhibits superior broadband photovoltaic performance, achieving a responsivity of 993 mA/W and an EQE of 131%. Furthermore, we developed a 4 × 4 photodetector array integrated with compressive sensing to facilitate rapid multi-dimensional photocurrent acquisition. Coupled with frequency modulation spectroscopy (FMS), this system enables the precise, non-destructive prediction of multi-wavelength optical rotation in liquid pharmaceuticals, demonstrating significant potential for advanced medical diagnostics.