The practical application of lithium (Li) metal anodes in high-capacity batteries is impeded by the formation of hazardous Li dendrites. To address this challenge, this research presents a novel methodology that combines laser ablation and heat treatment to precisely induce controlled grain growth within laser-structured grooves on copper (Cu) current collectors. Specifically, this approach enhances the prevalence of Cu (100) facets within the grooves, effectively lowering the overpotential for Li nucleation and promoting preferential Li deposition. Unlike approaches that modify the entire surface of collectors, our work focuses on selectively enhancing lithiophilicity within the grooves to mitigate the formation of Li dendrites and exhibit exceptional performance metrics. The half-cell with these collectors maintains a remarkable Coulombic efficiency of 97.42% over 350 cycles at 1 mA cm(-2). The symmetric cell can cycle stably for 1600 h at 0.5 mA cm(-2). Furthermore, when integrated with LiFePO4 cathodes, the full-cell configuration demonstrates outstanding capacity retention of 92.39% after 400 cycles at a 1C discharge rate. This study introduces a novel technique for fabricating selective lithiophilic three-dimensional (3D) Cu current collectors, thereby enhancing the performance of Li metal batteries. The insights gained from this approach hold promise for enhancing the performance of all laser-processed 3D Cu current collectors by enabling precise lithiophilic modifications within complex structures.

Wideband perfect absorbers are widely demanded for various applications, including efficient photodetection, radiation cooling. However, achieving perfect absorption across an extensive range of wavelengths on engraved structured substrate remains a challenge due to the complex light responses. It presents a hierarchical conical metasurface that demonstrates distinct perfect absorption from visible to far-infrared range (0.4-16 mu m), which is composed of surface-engraved high aspect ratio nanogratings on microcones. The perfect absorption in the typical reststrahlen band of 4H-SiC primarily relies on a light-trapping-enhanced surface phonon polaritons (SPhPs) mechanism, where the microcones effectively confine and enhance the SPhPs excited by the nanogratings through light trapping. Outside the reststrahlen band, the dominant mechanism for light antireflection is the light trapping of microcones assisted by nanogratings, which act as an equivalent antireflection layer. The hierarchical cones exhibit exceptional broadband performance, achieving an average absorptance of 98% over the spectrum of 0.4-16 mu m with wide-angle feasibility, and are fabricated using one-step ultrafast-laser ablation with ring-shaped vector beams. Notably, the hierarchical cones can be applied to various materials, showing significant potential for use in photodetectors. Wideband perfect absorbers are essential for photodetection and radiation cooling. In this paper, a novel hierarchical conical metasurface is introduced that achieves perfect absorption from visible to far-infrared wavelengths (0.4-16 mu m). Through the integration of surface-engraved nanogratings on microcones, the underlying mechanism, including surface phonon polaritons and light trapping, is examined. This technology holds significant promise for photodetection applications.image

Hierarchical micro/nanostructures have garnered considerable attention for their capabilities in light modulation, but the flexible fabrication of designed optical functional structures at both micro and nano scales remains challenging. Here, a polarization-modulated patterned laser ablation method complemented by flowing liquid is proposed to fabricate hierarchical microgrooves featuring tunable cross-sections and engraved surface nanostructures with controllable periods and orientations. The liquid-assisted ablation counters the shielding effect of ablation debris through laser-induced microjets, ensuring accurate control of the microgroove's shape by modulating the laser pattern in the focal plane. Simultaneously, the absence of debris also permits the consistent formation of laser-induced periodic surface structures (LIPSS) across the microgrooves. The LIPSS's period and orientation can be finely adjusted by manipulating the pulse energy and polarization within the patterned laser spot, facilitating the adaptable creation of hierarchical micro/nanostructures for optical application needs. As a demonstration, blazed gratings featuring orientation-customized LIPSS are fabricated, which exhibit polarization-dependent diffraction efficiency. The laser fabrication technique offers a highly versatile solution for sculpturing shape-controllable hierarchical gratings on hard-to-machine materials, paving the way for the swift production of customized optical elements. This work introduces a polarization-modulated patterned laser ablation method, complemented by flowing liquid, to fabricate hierarchical microgrooves featuring tunable cross-sections and engraved surface nanostructures with controllable periods and orientations. The laser fabrication technique offers a highly versatile solution for sculpturing shape-controllable hierarchical gratings on hard-to-machine materials, paving the way for the swift production of customized optical elements. image

Rigorously designed sub-micrometer structure arrays are widely used in metasurfaces for light modulation. One of the glaring restrictions is the unavailability of easily accessible fabrication methods to efficiently produce large-area and freely designed structure arrays with nanoscale resolution. We develop a patterned pulse laser lithography (PPLL) approach to create structure arrays with sub-wavelength feature resolution and periods from less than 1 μm to over 15 μm on large-area thin films with substrates under ambient conditions. Separated ultrafast laser pulses with patterned wavefront by quasi-binary phase masks rapidly create periodic ablated/modified structures by high-speed scanning. The gradient intensity boundary and circular polarization of the wavefront weaken diffraction and polarization-dependent asymmetricity effects during light propagation for high uniformity. Structural units of metasurfaces are obtained on metal and inorganic photoresist films, such as antennas, catenaries, and nanogratings. We demonstrate a large-area metasurface (10 × 10 mm 2 ) revealing excellent infrared absorption (3–7 μm), which comprises 250,000 concentric rings and takes only 5 minutes to produce.

Optical antireflection surfaces equipped with subwavelength nanocone arrays are commonly used to reach broadband supertransmissivity but are limited by the lack of wear resistance. We design and manufacture a structured surface with robust antireflection structures (R-ARS) composed of substrate-engraved nanocone arrays with micro-grid-shaped walls as protective armor. An ultrafast laser beam is used to selectively ablate and dope the metal from the deposited film into the subsurface of optical substrates to strengthen self-assembled nanoparticles formed during plasma etching as masks for nanocones. The untreated microscale metal grids serve as etching masks for the remaining protective armor. The geometrical features of nanocones and spatial distribution of protective armor with a proper duty cycle are theoretically optimized for improvement in both transmissivity and mechanical robustness. We demonstrate armored dense engraved nanocone arrays (with tip diameters of ∼50 nm and heights of ∼0.8 μm) on visible fused silica and infrared semi-insulating SiC with protective micro-square-grid armor. The average transmittances are improved from 93% to over 97% (on 0.4-1.2 μm) for double-face-structured fused silica, and from 60 to 65% (on 3-5 μm) for single-face-structured SiC, with few reductions of fused silica after 150 cycles of severe abrasion (under a pressure of 5.34 MPa) proving the excellent mechanical robust performance of R-ARS.

This paper proposes a one-step maskless 2D nanopatterning approach named self-aligned plasmonic lithography (SPL) by line-shaped ultrafast laser ablation under atmospheric conditions for the first time. Through a theoretical calculation of electric field and experimental verification, we proved that homogeneous interference of laser-excited surface plasmon polar-itons (SPPs) can be achieved and used to generate long-range ordered 2D nanostructures in a self-aligned way over a wafer-sized area within several minutes. Moreover, the self-aligned nanostruc-tures can be freely transferred between embossed nanopillars and engraved nanoholes by modulating the excitation intensity of SPPs interference through altering the incident laser energy. The SPL technique exhibits further controllability in the shape, orientation, and period of achievable nanopatterns on a wide range of semiconductors and metals by tuning processing parameters. Nanopatterned films can further act as masks to transfer structures into other bulk materials, as demonstrated in silica.