The growing demand for electromagnetic dissipation in electronic and information technologies has prompted continuous innovation in microwave absorbers. However, conventional designs are often based on uniform structures, which face limitations in achieving simultaneous low-frequency and broadband performance due to their limited geometric diversity and synergistic effects. To overcome these challenges, we propose a multiscale resonant labyrinth metastructure that is designed with multiple combinations of cavity dimensions. This metastructure was fabricated via Fused Deposition Modeling (FDM) using a polyether ether ketone/flaky carbonyl iron particles (PEEK/FCIPs) composite. Simulation and experiment have demonstrated that the metastructure synergistically integrates multiple dissipation mechanisms, including quarter-wavelength resonance, multicavity resonance, and edge diffraction. The finally optimized design exhibits an effective absorption bandwidth from 2.04 to 16.02 GHz, with a strong absorption band (below −15 dB) covering 2.49–9.04 GHz at a 10 mm thickness. Experimental results agree well with the simulations, and also reveal excellent angular stability that maintains effective absorption up to 45° for both transverse electric (TE) and transverse magnetic (TM) polarizations. This work provides an innovative structural design strategy to overcome conventional absorption performance limits, particularly in low-frequency absorption, showing significant promise for practical electromagnetic protection applications. • Multiscale resonant metastructure was proposed for low-frequency extension. • Parameters of multiple labyrinth cavities were investigated and combined. • Low-frequency enhancement and broadband absorption properties were achieved. • 3D printing compatible with the sophisticated multiscale metastructure.

Lead-free tin halide perovskites constitute a nontoxic alternative to lead-based solar absorbers, but their development is stifled by low performance and material instability, attributed primarily to Sn 2+ oxidation, high levels of defects, and slow charge transfer. We demonstrate glycine-functionalized Ti 3 C 2 T x MXene (MXG) as a multifunctional additive in FASnI 3 perovskite films. The amino groups on MXG have a two-fold role in that they chemically passivate the under-coordinated Sn sites and iodine vacancies, while at the same time provide moderate reductants to suppress Sn 2+ oxidation. Aside from passivation, the MXene with layered conductive properties also acts as a favorable template for perovskite crystallization, allows the vertical grain orientation for better light absorption into absorber layer, improves interfacial connection between layers and charge carrier transfer/extraction. For the MXG devices, better film quality and reduced trap state density and carrier lifetime with enhanced energy level alignment were observed. The champion MXG/FASnI 3 device shows a power conversion efficiency of 15.82% with improved stability (maintaining over 94% of its initial efficiency after 1000 hours). This investigation highlights the dual electrical and structural benefits of MXene engineering toward achieving earth‐abundant, efficient, stable, and scalable Sn perovskite PVs.

The pure MoS, binary ZnS/MoS, and ternary ZnS/MoS/composites incorporated with carbonaceous materials such as SWCNT, MWCNT, and GO nano-composites are synthesized using a hydrothermal technique. The compositions of the pure, binary, and ternary nano-composites are maintained at ratios of 100, 90:10, and 86:10:4, respectively. The XRD analysis confirmed the formation of a hexagonal single-phase structure. The surface morphology revealed well-defined nano-spheres with clear boundaries. Among the prepared materials, the ternary ZnS (86 %)–MoS (10 %)–GO (4 %) composite exhibited excellent electrochemical performance, delivering an average specific capacitance of 1098 F/g at various scan rates. It also demonstrated a high energy density of 1093 Wh/kg and a power density of 9.3 W/kg. A predominant pseudocapacitive charge-storage behavior is observed, with a diffusive contribution of 85.47 % at a scan rate of 5 mV/s, indicating its potential as a promising candidate for advanced energy storage systems. The enhanced electrochemical performance is attributed to the synergistic effect of transition metal sulfides combined with carbonaceous materials.