Physics

ABSTRACT Electrocatalytic NO 3 − ‐to‐NH 3 conversion offers a sustainable route for NH 3 production, yet its efficiency and selectivity are limited by the requirements of strong NO 3 − adsorption, efficient intermediates hydrogenation, and suppressed hydrogen evolution reaction (HER). Tungsten‐based oxides strongly adsorb NO x intermediates but show poor hydrogenation capability, whereas Ni‐based oxides efficiently dissociate H 2 O to promote hydrogenation yet often induce excessive HER. Herein, we construct an oxygen‐bridged NiO/WO 3 heterostructure to reconcile these functions via interfacial electronic modulation. Spectroscopic analyses reveal pronounced electron transfer across the W–O–Ni interface, generating electron‐enriched W(VI) and electron‐deficient Ni(II) species. These dual active sites optimize NO x adsorption on W sites while regulating proton availability at Ni sites, enabling stepwise hydrogenation with suppressed HER. The NiO/WO 3 heterostructure achieves Faradaic efficiency of 96.1 ± 3.4% and NH 3 yield rate of 9.2 mg h −1 cm −2 at −0.5 V vs. RHE, outperforming individual WO 3 and NiO. In‐situ infrared spectroscopy confirms moderated NO x adsorption‐desorption and weakened hydrogen adsorption, while density functional theory calculations confirms that oxygen‐bridged interfacial bonding optimizes NO x binding and attenuates HER. Furthermore, a NiO/WO 3 ‐based Zn–NO 3 − battery delivers a power density of 27.1 mW cm −2 . This work establishes an oxygen‐bridge‐mediated heterostructures enable precise dual‐site electronic regulation for selective NO 3 − ‐to‐NH 3 electrocatalysis.

ABSTRACT Anion exchange membrane seawater electrolysis (AEMSE) is crucial for future large‐scale green hydrogen production, however enduring a challenge that lacks high‐durable oxygen evolution reaction (OER) electrocatalysts. We report a porous aerogel composed of Ni/Cr 2 O 3 nanoparticles anchored on P‐RuO 2 nanofibers (Ni/Cr 2 O 3 @P‐RuO 2 ). The Cr 2 O 3 @P‐RuO 2 aerogel exhibits low overpotentials of 220/27 mV@mA cm −2 for OER and HER in alkaline seawater, and maintains stable operation for 500 h@0.1 A cm −2 when assembled in an AEMSE. X‐ray absorption near‐edge structure (XANES) analysis combined with density functional theory (DFT) calculations collectively reveal that a multi‐metallic synergistic effect induces electron transfer from Ni/Cr 2 O 3 to Ru. Additionally, Ru exhibits unsaturated coordination defects as catalytic active sites, thereby enhancing catalytic activity. In situ Raman spectroscopy and time‐of‐flight secondary ion mass spectrometer (TOF‐SIMS) confirm the formation of on the catalyst surface, thereby enhancing corrosion resistance through electrostatic repulsion. In addition, highly dispersed Cr 2 O 3 particles prevent RuO 2 overoxidation and deactivation during the OER. Meanwhile, they serve as Lewis acid sites and synergistically collaborate with to form a surface micro‐environment with high selectivity toward OH − . Molecular dynamics simulations validate the establishment of this dual anti‐corrosion mechanism, achieving a breakthrough in addressing catalyst durability limitations during seawater electrolysis.

ABSTRACT The selective oxidation of hydrocarbons with molecular oxygen (O 2 ) is a pivotal but energy‐intensive process, with the primary energy consumption arising from the activation of the robust O═O bond. While emerging organic photocatalysts offer a sustainable route for O 2 activation under mild conditions, the prevailing mental model often involves first generating H 2 O 2 as an intermediate oxidant. Consequently, the scalable construction of efficient metal‐free systems capable of directly coupling O 2 activation with selective transformations remains a formidable challenge. Herein, a 3D, spatially π‐extended triphenylene framework (HCP‐TP‐FDA) is synthesized scalably via a simple Friedel–Crafts reaction. This hyper‐cross‐linked polymer bypasses complex monomer design and exhibits outstanding photocatalytic performance in O 2 activation. This unique capability enables efficient H 2 O 2 production (5.57 mmol g −1 h −1 ) and selective oxidation of cyclohexane to KA oil (515 µmol g −1 h −1 ) and the hydroxylation of phenol to dihydroxybenzene (167 µmol g −1 h −1 ). Mechanistic studies reveal that the synergy between electron‐rich triphenylene units and 3D conjugation facilitates directional charge migration along organized π–π stacks—a mechanism reminiscent of natural light‐harvesting systems. This process effectively promotes exciton dissociation and O 2 activation, leading to the versatile generation of reactive oxygen species.

ABSTRACT Defect‐induced lattice distortion and thermally induced lattice expansion result in lattice strains in the perovskite film. Suppressing the lattice strain is significant for improving efficiency and stability of perovskite solar cells (PSCs) but remains challenging. Herein, we report a strain inhibition strategy by treating the intermediate‐state perovskite (Inter‐PVK) film pre‐annealed at a low temperature using a boronic acid‐based molecule. The boronic acid group interacts with ionic defects on the surface of the Inter‐PVK film, in favor of reducing defect‐induced lattice distortion in the final‐state perovskite film during its downward growth process. The interaction also immobilizes organic components, preventing their volatilization and consequently inhibiting the lattice expansion. Both aspects synergistically mitigate the lattice strain throughout the entire perovskite film. The resultant low‐strain perovskite film enables an efficiency of 26.32% for inverted PSCs (certified 26.20%) and 25.57% for regular PSCs, respectively. Moreover, the devices retain 94% of their initial efficiency after 1500 h of continuous 1‐sun light soaking. Our work provides a new strategy for regulating strains in perovskite films to enhance PSC performances.

ABSTRACT Monolithic perovskite/silicon tandem solar cells are highly attractive due to their potential for high power conversion efficiency (PCE). In tandem solar cells, the perovskite top cell and silicon bottom cell are connected via a recombination layer, and the quality of this interface directly affects carrier transport and recombination. However, in silicon heterojunction (SHJ) cells–particularly on micro‐pyramidal (∼600 nm‐thick) textured surfaces, optical losses in the composite layer and non‐uniform coverage of the self‐assembled monolayer (SAM) remain challenging. Here, we investigated the optoelectronic properties of indium tin oxide (ITO) composite layers with thickness ranging from 2 to 30 nm, by optimizing the intermediate composite layer, optical losses in perovskite/silicon tandem solar cells were effectively reduced, and surface potential uniformity was enhanced. We selected an ultra‐thin (8 nm‐thick) ITO layer modified with nickel oxide (NiO x ), which was implemented as a composite interconnect, with a Poly‐SAM layer employed to realize these enhancements. Compared to the reference thickness, the optimized device exhibited an increase in short‐circuit current density of 0.85 mA cm −2 , achieving a high value of 20.82 mA cm −2 , and a power conversion efficiency of 31.80 % was achieved, and 96 % of the initial PCE was retained after 500 h of maximum power point tracking.

Abstract Capacitance, photon detection probability (PDP), and dark count rate (DCR) constitute the primary performance metrics for single-photon avalanche diodes (SPADs) in weak-light detection applications. Understanding their interdependencies and trade-offs is essential for optimal device design, particularly as miniaturization and integration trends intensify. This work investigates the size-dependent performance characteristics of two distinct SPAD structures (STR A and STR B) fabricated by a standard 0.18-μm BCD process. Through combined experimental measurements and TCAD simulations, we systematically analyze the basic coupling mechanism between device size and these three parameters. It establishes a quantitative relationship among junction size and device performance, and introduces the edge ratio metric as a design parameter. providing practical guidelines for SPAD integration and high-precision timing detection.

We present a high-speed infrared spectroscopic ellipsometer using a tunable quantum cascade laser (QCL), leveraging its high brightness for potential in situ and in-line monitoring applications. The instrument employs a dual-rotating-element configuration comprising an achromatic Fresnel rhomb-type rotating compensator and a rotating analyzer, enabling acquisition of 3 × 4 Mueller matrix elements over a wavelength range defined by the installed QCL laser modules. We demonstrate the measurement speed of the QCL ellipsometer and its advantages relative to conventional Fourier-transform infrared ellipsometry through a series of case studies, including measurements of complex molecular vibrations of acrylic and polycarbonate, anisotropic phonon absorption of LiNbO3 single crystal, and its temperature-dependent response. Additionally, we perform time-dependent measurements during the thermal growth of an SiO2 film on Si, highlighting the instrument's capability for real-time process monitoring.

The effects of scattering channels in high operating temperature terahertz quantum cascade laser structures are studied. The electron transport is calculated using a density matrix Monte Carlo method, where the scattering channels are isolated to determine their effects by including and excluding each channel in the transport calculations. Scattering channels leaking to the continuum and from the longitudinal-optical phonon interaction are considered. All channels investigated except one are found to decrease the maximum operating temperature, and only phonon backscattering to the upper lasing state enhances thermal performance. Improving the isolation of scattering channel states is expected to further increase the operating temperature, with thermal backfilling to the lower lasing state dominating.

Electron emission from boundaries is ubiquitous in radio-frequency capacitively coupled plasmas (RF-CCPs) and can exert a significant influence on discharge characteristics. In this work, particle-in-cell Monte-Carlo collisions (PIC-MCC) simulations with an external circuit are performed to investigate a conduction-current-dominated RF-CCP mode, termed the inverted RF-CCP, which is induced by strong boundary electron emission. In this mode, the displacement current becomes negligible, and the conduction current dominates in both bulk plasma and sheaths, as opposed to the classic RF-CCPs. The inverted RF-CCP also features weak resistive sheaths, and the plasma impedance is dominated by a resistive–inductive bulk region due to sheath inversion. Parametric scan of neutral pressure reveals the origin of the observed phase behavior. These findings provide practical methods for diagnosing the inverted RF-CCP, based on its distinctive impedance signature without direct sheath diagnostics. Additionally, we show that unbalanced electron emission can generate discharge asymmetry, enabling a unidirectional ion flow between electrodes.