Industrial deployment of perovskite/silicon tandem solar cells is limited by the difficulty of forming thick, defect-controlled wide-bandgap (WBG) perovskite layers that conformally coat micron-textured silicon while retaining interfacial passivation. Here, we introduce a diffusion-driven macromolecular passivation strategy (DMPS) employing a π-extended zinc phthalocyanine derivative (ZnPc-C12) that simultaneously regulates perovskite crystallization and mitigates interfacial defects. Interfacial-energy gradients created during solvent evaporation impose a thermodynamic driving force that expels ZnPc-C12 from the bulk toward both interfaces, establishing dual-interface passivation and uniform 1.5 µm WBG perovskite films on industrial Czochralski silicon heterojunctions. The resulting single-junction devices achieve 24.26% power-conversion efficiency, while monolithic tandems deliver 34.26% (certified 33.83%) efficiency and > 90% retention after 800 h of continuous operation. DMPS provides a general and scalable pathway for integrating defect-controlled perovskite absorbers into textured silicon architectures, advancing the manufacturability of next-generation film-on-wafer tandem photovoltaics.

Carbazole-based self-assembled monolayers (SAMs) were widely adopted as hole-selective layers (HSLs) and recombination junction material in perovskite/silicon tandem solar cells (P/S-TSCs), yet it remains challenging to simultaneously suppress excessive molecular aggregation and maintain continuous charge-transport pathways, particularly on textured silicon substrates. Herein, we report series of sterically extended asymmetric carbazole-based SAMs, 4-(11H-benzo[a]carbazol-11-yl)benzoic acid (BABCz), 4-(9H-dibenzo[a,c]carbazol-9-yl)benzoic acid (BADBCz), and 4-(3',6'-dimethoxy-9H-[3,9'-bicarbazol]-9-yl)benzoic acid (MeO-BADCz), in which MeO-BADCz engineers to construct a continuous three-dimensional C-H···π-mediated charge-transport network while effectively restraining long-range crystallization. The MeO-BADCz monolayer combines strong anchoring to substrate, pronounced work-function modulation, and efficient defect passivation at the buried interface, enabling pinhole-free, highly crystalline wide-bandgap (1.68 eV) perovskite films with suppressed non-radiative recombination. Through these advancements, the optimized wide-bandgap perovskite solar cells (PSCs) incorporating MeO-BADCz as the HSL deliver a power conversion efficiency (PCE) of 24.05% with negligible hysteresis and retain 97.1% of their initial efficiency after 1000 h of continuous operation under ISOS-L-1 protocol. When implemented as the recombination layer on textured silicon heterojunction (SHJ), MeO-BADCz further enables P/S-TSCs with a certified PCE of 33.04% and robust stability under damp-heat-light conditions. This work demonstrates a steric-engineering concept for asymmetric carbazole-based SAMs and highlights texture-tolerant multidimensional charge-transport networks as a key motif for scalable tandem photovoltaics.

Accurate intraoperative margin assessment is critical for complete resection of solid tumours. However, surgeons routinely rely on manual palpation, which is highly subjective and fundamentally limited by poor spatial resolution, and pre-operative imaging lacks real-time feedback. While emerging optical elastography techniques offer quantitative mechanical contrast, their reliance on bulky optical components necessitates cumbersome alignment and hinders integration into miniaturised surgical instruments. Here, we report metalens stereoscopic optical palpation (MSOP), a nanophotonic imaging platform leveraging a binocular metalens integrated with a single CMOS sensor to achieve high-fidelity, self-aligned elastography. By replacing complex bulk optics with a compact stereoscopic architecture, MSOP enables robust, high-contrast mapping of tissue surface stress. Following validation in heterogeneous silicone phantoms, we demonstrate MSOP's translational potential by characterising the mechanical signatures of malignancies in fresh mouse pancreatic cancer models, as well as excised human breast and liver specimens. By providing reliable, label-free mechanical contrast across diverse oncological landscapes, MSOP offers a compact tool for precise intraoperative margin delineation to reduce re-excision rates and improve surgical outcomes.

Textured Czochralski-grown silicon (CZ-Si) integrated with metal halide perovskites present a promising strategy toward low-cost and high-efficiency tandem photovoltaics due to their superior light-trapping capabilities. The challenges in the perovskite/silicon tandem solar cells (P/S-TSCs) is the hole-selective layers (HSLs) that facilitate efficient charge extraction while preventing interfacial shunting. Self-assembled monolayers (SAMs) often suffer from incomplete coverage and limited reproducibility on textured surfaces. In this study, we present a novel self-assembling molecule, 5-(11H-benzo [a]carbazol-11-yl)isophthalic acid (IPABCz), designed with extended It-conjugation and dual anchoring functionality that demonstrates remarkable texture tolerance on CZ-Si. To fabricate wide-bandgap (similar to 1.68 eV) single-junction perovskite solar cells, devices utilizing IPABCz as the hole transport layer (HTL) achieved a champion power conversion efficiency (PCE) of 21.36 % and exhibited an almost negligible hysteresis of 0.94 %. Notably, the highest PCE recorded for the P/S-TSC based on IPABCz as HSL on textured CZ-Si reached up to 30.56 %. Importantly, both device configurations highlight significant improvements in stability. These findings provide a viable strategy for designing texture-tolerant HSLs that can enhance performance in tandem photovoltaic applications.

ABSTRACT Understanding the intrinsic coupling between electrical conductivity (σ) and the Seebeck coefficient (S) remains a central challenge in organic thermoelectrics, where energetic disorder and charge transport are highly sensitive to molecular design. Here, we show that precise control over the side‐chain branching position provides an effective structural lever to tune the σ–S relationship in conjugated polymers. Two DPP–selenophene copolymers with identical backbones but branched at distinct positions exhibit markedly different molecular packing, charge‐carrier delocalization, and density‐of‐states (DOS) widths. Polymers with more distant branching points form tighter π–π stacks, yielding enhanced carrier mobility and a narrower DOS that collectively boost σ to 129.3 S cm−1. In contrast, closer branching induces greater energetic disorder and broader DOS distributions, resulting in a substantially higher S of 160 µV K−1. Despite their contrasting transport characteristics, both polymers deliver similar peak power factors owing to complementary changes in σ and S. These results identify side‐chain branching as a previously underappreciated design parameter that mechanistically governs the coupling between conductivity and Seebeck coefficient in organic thermoelectric materials.

Optical metasurfaces have catalysed transformative advances across imaging, optoelectronics, quantum information processing, sensing, energy conversion, and optical computing. Yet, most current research remains constrained by the challenge of integrating multiple functions within a single device. Inspired by the aesthetic of disordered mosaics in art, we demonstrate that by engineering structural disorder of meta-pixels to implement a photonic function, the active area required can be considerably reduced, without compromising optical performance. Without increasing the design complexity, the remaining unallocated space can be repurposed to encode functionally distinct meta-pixels, each independently addressable via various optical degrees of freedom. To demonstrate the universal adaptability of our approach, we present two proof-of-concept examples including an achromatic metalens - that operates across the 1200-1400 nm spectral window and with a scalable aperture size up to 8.1 mm - and single-shot, high-spatial-resolution polarimetric imaging of arbitrarily structured light fields. This disordered mosaic metasurface platform establishes a versatile foundation for integrating diverse photonic functionalities within a single diffractive optical element, representing a substantial step toward compact, high-density, multifunctional optical devices.

Defect passivation using aromatic molecules is an effective strategy to suppress trap states and non-radiative recombination in perovskite solar cells (PSCs). However, the correlation between molecular configuration and interfacial carrier dynamics remains elusive, as prior studies largely focus on adsorption strength and energy-level alignment while neglecting adsorption regularity and configurational completeness at grain boundaries. Herein, 2,4,6-tri(1H-pyrazol-4-yl)pyridine (PYTPZ) is introduced as a grain-boundary passivator. PYTPZ molecules are preorganized into nanoscale hydrogen-bonded organic frameworks, enabling controllable configuration. The exposed peripheral functional groups induce a tilted lattice stacking with perovskite, forming an ordered "standing" configuration with reduced steric hindrance and enhanced interfacial coverage. This geometry localizes the passivator HOMO and aligns excited-state transitions with interfacial charge transfer, thereby promoting charge separation. In contrast, a "lying" configuration leads to excessive orbital overlap and ineffective hole trapping. Consequently, the standing configuration facilitates efficient hole extraction and suppresses non-radiative recombination, delivering a champion efficiency of 25.63% (24.85% for 1 cm2 devices) with markedly improved stability.

The inorganic perovskite solar cells (PSCs) exhibit superior thermal stability to the organic-inorganic hybrid PSCs. However, halide defects with low formation energy are often present at grain boundaries of the inorganic perovskite films. This results in many defects of Pb2+ uncoordinated with halides, causing in non-radiative recombination in the films. In this work, cesium fluoride (CsF) was chosen as an additive in the CsPbI2Br precursor solution, in which Cs+ can passivate the A-site vacancy defects in CsPbI2Br perovskite films; fluoride ion (F-) has a smaller ionic radius and is more electronegative than chloride ion (Cl- ), iodide ion (I-), and bromide ion (Br- ), which may allow it to fit in the smaller spaces in the host lattice, as well as weaken the lattice strain and improve the stability of the desired phase. Based on this strategy, CsF-treated carbon-based hole-transportlayer-free CsPbI2Br PSCs were obtained with a champion photovoltaic conversion efficiency of 13.45 %, shortcircuit current density of 15.15 mA/cm2, open-circuit voltage of 1.18 V, and fill factor of 75 %. Meanwhile, the CsF-treated CsPbI2Br PSCs possessed better environmental stability compared to the un-treated counterpart due to the introduction of the more hydrophobic F- . This strategy provides a simple and feasible strategy for the development of efficient and stable inorganic PSCs.

Carbon nanotube (CNT) cathode materials exhibit excellent electron emission performance and have become a key research focus in the field of vacuum electronics. However, their practical applications are still restricted by challenges, including emission instability and ambiguity in temporal resolution capability. This work investigated the thermal-assisted field emission characteristics of CNT and their application in pulsed X-ray imaging. Systematic characterization of the turn-on field strength, emission stability, pulse response characteristics, and pulsed X-ray imaging performance demonstrated that the thermal-assisted operating mode reduced current fluctuations to below 1%. Increasing the heating power further enhanced emission stability and lowered the turn-on field strength. In thermal-assisted pulsed emission mode, CNT cathodes exhibited reduced power consumption compared to conventional thermionic cathodes and achieved microsecond-scale pulse response. Further X-ray imaging experiments confirmed that the X-ray dose generated by CNT in this operational mode exhibited higher stability, enabling 100 μs pulsed imaging and clear visualization of rotating blades operating at 600 Hz. This study validated the feasibility of CNT cathodes for high-speed X-ray imaging and could provide a reference for the development of advanced pulsed X-ray sources and related technologies.

In transition metal dichalcogenides, the valley degree of freedom directly couples valley-polarized excitons, excited by circularly polarized light to valley-dependent chiral photons, enabling ultrafast light-driven valleytronics. However, achieving fully integrated valley optoelectronics, incorporating on-chip in situ generation, selective routing and electrical readout of valley-dependent chiral photons, remains an unresolved challenge. Here we present a valley-driven hybrid optoelectronic nanocircuit that integrates chirality-selective meta-waveguide photodetectors with transition metal dichalcogenides. At room temperature, our purposely designed meta-waveguide device generates near-unity valley-dependent chiral photons in the second-harmonic generation from an encapsulated tungsten disulfide monolayer and selectively couples them to unidirectional waveguide modes, achieving an exceptional polarization selectivity of 0.97. These valley-dependent waveguide modes were subsequently detected by atomically thin few-layer tungsten diselenide photodetectors, exclusively responsive to the above-bandgap upconverted photons, thereby enabling all-on-chip processing of valley-multiplexed images. Our demonstration bridges a critical gap in lightwave valleytronics, paving the way for compact, programmable and scalable valley information processing and fostering the development of light-based valleytronic quantum technologies.

Nonlinear optical metasurfaces have emerged as a powerful platform for efficient and multi-dimensional manipulation of harmonic waves, offering distinct advantages such as high-integration capability and phase-matching-free operation. Spin and orbital angular momentum (SAM and OAM) provide rich degrees of freedom for advanced light field control. While SAM- and OAM-multiplexing metasurface holograms have been realized in the linear optical regime, their performance is hindered by a low signal-to-noise ratio stemming from residual light mode conversion. Nonlinear OAM holography has recently been demonstrated; however, its practicality remains limited by reliance on bulky nonlinear optical crystals that exhibit only intrinsic spin-orbit interaction (SOI). Here, we introduce nonlinear SOI holography via second harmonic generation on optical metasurfaces composed of gold plasmonic meta-atoms. By controlling the local rotational symmetry and topological charges, these metasurface holograms can fully harness optical SOI through both intrinsic and extrinsic angular momentum mode conversions. Information hidden in second harmonic holographic images can only be reconstructed from the spin-orbit tomography of the fundamental waves, ensuring high-security nonlinear optical encryption. The proposed approach offers promising applications in optical communications, optical information processing, high-dimensional optical storage, and so on.

Quantum skyrmions are topological structures that have garnered significant interest due to their demonstrated robustness and versatility across diverse optical platforms. However, existing approaches for their generation are limited to producing pre-determined two dimensional qubit states with a single topology. Here we create multi-dimensional topological states by introducing a non-local interaction between high-dimensional photonic entanglement and a metasurface, where the topological transformation induced by the metasurface is made non-deterministic by the probabilistic nature of the interfacing entangled state. Within this framework, we demonstrate that individual quantum states can host multiple co-existing topologies that are only revealed upon measurement, allowing for their parallel transport within distinct spatial mode channels. We confirm this by revealing the rich topological landscape within our modified Hilbert space while controlling the desired output topology by orbital angular momentum (OAM) projections on one of the entangled photons, producing multiple non-local polarization-OAM entangled states characterized by distinct topological classes, all from a single metasurface device. Our results reveal new capability when structured high-dimensional entanglement is interfaced with structured matter capable of coupling photonic degrees of freedom, establishing a new pathway for the compact generation of complex quantum states.

Work function modulation of transparent conductive oxides via self-assembled monolayers (SAMs) facilitates efficient hole or electron extraction in optoelectronic devices. However, recent SAMs for perovskite solar cells (PSCs) diverge from traditional interfacial dipole orientation design principles, instead leveraging electron-rich and electron-deficient surface modifications. In light of these discrepancies, this study systematically analyses electron-deficient materials of varying strength, revealing the dominance of surface modifications over interfacial dipole orientation. Specifically, modulating the electron-withdrawing strength by replacing the carboxylic acid group (Bpy-COOH) with a cyanoacrylic acid moiety (Bpy-CAA) in dual-functional bipyridine-based electron-selective molecular layers (ESMLs) enhances adsorption, electron extraction, and passivation in n-i-p PSCs. Consequently, Bpy-CAA devices achieve 23.98% efficiency, surpassing Bpy-COOH-based devices (23.20%), and maintain an impressive 21.63% efficiency in 1 cm2 cells, the highest reported for 1 cm2 n-i-p PSCs utilizing organic ESMLs. A remarkable efficiency of 26.00% is achieved by integrating Bpy-CAA as an interfacial layer into SnO2/ESML/perovskite contacts while adapting this architecture into four-terminal perovskite/silicon tandem solar cells (4T-P/STSCs) yields an impressive efficiency of 30.83%, ranking among the highest reported efficiencies for 4T-P/STSCs. Overall, this work demonstrates that the electronic nature of the molecule is more decisive than dipole orientation for efficient electron extraction, and tailoring the dual-functional ESMLs effectively facilitated the development of efficient single-junction PSCs and 4T-P/STSCs.

Circular dichroism, arising from interactions with light fields of opposite spin angular momentum, has become a fundamental tool for molecular characterization. Meanwhile, helical dichroism (HD) - the dichroic response to vortex beams carrying opposite orbital angular momentum (OAM) - offers an alternative approach for probing chiral molecules and photonic structures. Previous demonstrations of HD have been limited to non-resonant light-matter interactions with chiral micro- and nanostructures, leaving the realization of resonance helical dichroism largely unexplored. Here, we present the design and implementation of twisted dielectric metastructures, composed of an array of rotated silicon trimer nanostructures harnessing nonlocal photonic modes with a high quality factor of several dozen that enable strong resonant HD for OAM values up to 10. We experimentally demonstrate resonantly enhanced HD for strongly focused OAM beams with the magnitude of topological charges from 1 to 3. Our findings pave the way for resonant nanophotonics involving OAM beams, unlocking the full potential of structured light for applications in molecular sensing, optical imaging, nonlinear optics, and optical data storage.

A stable and durable ultrafast electron source is highly desirable for sophisticated vacuum electron technologies. However, free-space excitations based on ultrahigh-power or deep-ultraviolet pulsed lasers usually cause cathode material damage and mechanical vibration even under ultrahigh vacuum. In this work, we present a compact ultrafast electron source consisting of graphene integrated on an optical fiber, taking advantage of the ultrafast hot-electron emission from graphene and well-defined single-mode excitation from the optical fiber. With mild excitation (~1 GW/cm2, infrared laser), an ultrashort electron pulse (width of ~ 80 fs) with high stability (fluctuation ≤±0.5% in 8 hours) and longevity (T90 > 500 hours) can be generated even under relatively high ambient pressure (up to 100 Pa). This compact source has been facilely integrated into a commercial electron microscope for time-resolved imaging and spectroscopy. Our graphene optical fiber-based ultrafast electron source offers a promising solution to support the development of vacuum electron instruments.

Emerging two-dimensional transition metal dichalcogenides (TMDCs) offer a promising platform for on-chip integrated photonics because of their unique optical and electronic properties. Their naturally passivated surfaces make them highly tolerant to lattice mismatch, enabling seamless heterogeneous integration by stacking different van der Waals materials, a crucial step in the development of advanced photonic devices. Here, we demonstrate the use of an inverse design wavelength demultiplexing waveguides for on-chip sorting and routing of distinct photoluminescence from the heterojunction formed by WS2 and WSe2 monolayers. The integrated nanophotonic chip splits and sorts excitonic emission into individual waveguides at room temperature. Our demonstration opens up new perspectives for integrating light sources in van der Waals materials with functional integrated photonics, offering a versatile platform for both fundamental research and practical applications.

Optical Stokes skyrmions represent an emerging class of structured light characterized by intricate topological polarization textures in the beam’s transverse plane. Traditional methods for generating Stokes skyrmions rely on bulky optical setups, driving significant interests in compact, single-device solutions. However, existing approaches fail to ensure propagation-invariant topology, an imperative requirement for advancing applications in this field. In this paper we address this fundamental challenge with a metasurface design based on structural birefringence and geometric phase which manipulates light in dynamic phase iso-curves, achieving arbitrary co-polarization to cross-polarization conversion while maintaining a constant dynamic phase. This design enables propagation-invariant topological features of optical skyrmions produced by a single generation device. Our framework offers a compact platform for shaping topologically stable optical skyrmions, which may stimulate their applications for long-range optical information transfer.

In transition metal dichalcogenides, the valley degree of freedom directly couples valley-polarised excitons - excited by circularly polarised light - to valley-dependent chiral photons, enabling ultrafast light-driven valleytronics. However, achieving fully integrated valley optoelectronics - incorporating on-chip generation, selective routing, and electrical readout of valley-dependent chiral photons - remains an unresolved challenge. We present a valley-driven hybrid nanophotonic-optoelectronic circuit that integrates chirality-selective meta-waveguide photodetectors with transition metal dichalcogenides. At room temperature, our purposely designed meta-waveguide device generates near-unity valley-dependent chiral photons in the second harmonic generation from an encapsulated tungsten disulfide monolayer and selectively couples them to unidirectional waveguide modes, achieving an exceptional polarisation selectivity of 0.97. These valley-dependent waveguide modes were subsequently detected by atomically thin few-layer tungsten diselenide photodetectors, exclusively responsive to the above-bandgap upconverted photons, thereby enabling all-on-chip processing of valley-multiplexed images. Our demonstration bridges a critical gap in lightwave valleytronics, paving the way for compact, scalable valley information processing and fostering the development of light-based valleytronic quantum technologies.

Quantum sensing based on solid-state spin defects provides a uniquely versatile platform for nanoscale magnetometry under diverse environmental conditions. Operation of most sensors used to-date is based on projective measurement along a single axis combined with computational extrapolation. Here, we show that an individually addressable carbon-related spin defect in hexagonal boron nitride is a multi-axis nanoscale sensor with large dynamic range. For this spin-1 system, we demonstrate how its spin-dependent photodynamics give rise to three optically detected spin resonances that show up to 90% contrast and are not quenched under off-axis magnetic field exceeding 100 mT, enabling $$\mu \,{{\rm{T}}}/{{{\rm{Hz}}}^{-1/2}}$$ μ T / Hz − 1 / 2 sensitivity. Finally, we show how this system can be used to unambiguously determine the three components of a target magnetic field via the use of two bias fields. Alongside these features, the room-temperature operation and the nanometer-scale proximity enabled by the van der Waals host material further consolidate this system as a promising quantum sensing platform.

Although lots of efforts have been devoted on new less hygroscopic dopants to address problems in hole transport materials (HTM), the long-time post-oxidation and the volatilization of 4-tert-butylpyridine (tBP) are still issues. A new doping mechanism for spiro-OMeTAD by disulfiram (TETD) is revealed in this work. Owing to its disulfide bond, TETD can be activated easily to produce reactive sulfur for the rapid oxidation of spiro-OMeTAD in the absence of oxygen with formation of [spiro-OMeTAD•]+[SC(S)N(C2H5)2]-. Thus, in this situation, the Li+ ion has the opportunity to coordinate tBP and fix each other in HTM film. DFT calculations suggest that the resulting favorable energy (with a ΔE of -1.29 eV) must come from the mutual interactions among Li+, TFSI−, and tBP, which is different from the well-known doping process that tBP would not participate in the doping reaction. As a result, the introduction of a new radical into the HTM greatly reduce device performance fluctuations due to the environmental dependence and inhibit tBP volatilizing for enhanced long-term stability.