Multivalent defects share a conserved total concentration among charge states, whereas device simulations often represent each transition by an independent Shockley–Read–Hall (SRH) center. A nine-model TCAD ablation is used to separate errors from recombination statistics and self-consistent defect-charge feedback. The comparison covers SeSb in an Sb2 Se3 solar cell and PtSi in a Si field-stop insulated-gate bipolar transistor (IGBT), using the full shared-density Sah–Shockley model as the reference. For SeSb at low Nt, strong capture-coefficient asymmetry makes the 0/−1 pathway negligible, allowing one SRH center to approximate the reference; for PtSi, both transitions contribute and neither can be omitted. At low-to-moderate Nt, recombination-statistics differences dominate the independent-SRH error, whereas at high Nt, defect charge alters internal fields and carrier distributions. In the solar cell, the charge-coupled independent-SRH approximation retains errors in charge-state occupation, while the charge-decoupled Sah–Shockley model omits electrostatic feedback from defect charge; neither reproduces the reference at high Nt. In the IGBT, high Nt produces electron-dominated conditions that reduce trapped-charge differences, while more device regions enter low-RW ranges with smaller recombination-statistics differences; both effects yield similar terminal responses. Resistive-load switching further shows that steady-state agreement does not ensure consistent switching because pre-turn-off carrier storage and charge-state dynamics differ. The full model minimizes model-form risk when multiple transitions and electrostatic feedback matter, but requires complete transition parameters and 1.76–2.65 times the runtime of the charge-coupled independent-SRH approximation.
Memristors have great application prospects in neuromorphic systems, but there are inherent trade-offs between stability, switching ratio and adjustability of traditional memristors. Herein, we fabricate composition-tunable layered SnSxSe1−x (0 ≤ x ≤ 1) vertical memristors via low-pressure rapid physical vapor deposition and dry transfer, with switching behavior consistent with Sn-vacancy-assisted Ag conductive-filament dynamics. The Ag/SnS0.5Se0.5/Au device achieves an ultrahigh ON/OFF ratio of 1.68 × 107, a mean threshold voltage of 0.611 ± 0.064 V across 50 functional devices, and 800 cycles in one representative device. Moreover, it successfully emulates key synaptic functions including paired-pulse facilitation and long-term potentiation/depression. We establish an experimentally calibrated SPICE compact model and simulate a single-input threshold circuit. We further construct an open-loop memristor-driven motor system for measured DC motor-speed modulation rather than closed-loop unmanned aerial vehicles (UAV) thrust regulation. This work provides a proof-of-concept hardware platform for neuromorphic computing and open-loop actuation systems.
Carbon fiber reinforced polymer (CFRP) composites have been extensively utilized in the aerospace industry owing to their advantageous properties, including low weight, high strength and stiffness, excellent fatigue resistance, and design flexibility. However, their inherent lack of sufficient electrical conductivity presents a fundamental challenge concerning lightning strike damage. Both the direct physical damage and indirect electromagnetic effects induced by lightning strikes pose severe threats to flight safety. Conventional protection strategies employing metallic layers are often hindered by issues such as increased weight, susceptibility to corrosion, and interfacial compatibility problems with the composite substrate. Previous review articles have primarily focused on the testing and characterization of CFRP lightning damage, its manifestations and mechanisms, as well as simulation and prediction techniques. Other reviews have summarized research progress in enhancing the electrical conductivity of CFRP in various dimensions. Nonetheless, a systematic discussion dedicated specifically to non-metallic solution strategies for CFRP lightning strike protection (LSP) remains absent. Herein, this article provides a comprehensive review of the experimental research literature concerning non-metallic LSP approaches for CFRP. The reviewed strategies primarily encompass the fabrication of surface conductive layers, blending with nanofillers, fiber surface modification, interlayer enhancement, and the use of intrinsically conductive polymers and composites. Furthermore, this review discusses the existing challenges for LSP-CFRP, particularly regarding the balance between mechanical and electrical properties, process feasibility, and the need for multi-scale validation. It aims to offer valuable insights for the design and fabrication of high-performance, lightweight resin-based composites with integrated lightning protection capabilities.
Carbon fiber reinforced polymer composites (CFRPs) demonstrated enormous potential for applications in defense, aerospace, and high-end civilian products, owing to their lightweight, high strength, high modulus, and excellent high-temperature resistance. However, the surface of carbon fiber (CF) was chemically inert and lacks active functional groups, which resulted in poor interfacial bonding with polymer matrix. Consequently, the overall performance of the composites was limited. To address this question, various surface modification techniques have been developed to improve the surface reactivity, roughness, and wettability of CF. These improvement strategies had enhanced the interfacial adhesion between CF and the matrix, thereby improving the mechanical, electromagnetic and thermal properties of CFRPs. In recent years, graphene oxide (GO) has gained attention as a key nanomaterial for improving the interfacial and mechanical performance of CFRPs. This was attributed to its outstanding mechanical properties and abundant surface functional groups, such as hydroxyl and carboxyl groups. This review systematically summarised the main methods of modifying the surface of CF using GO and elucidated the mechanisms by which these modifications affect interfacial properties. Finally, we outlined the current challenges and future development trends in interface modification technology, aiming to provide theoretical guidance and technical support for the interfacial design and application of high-performance CFRPs.
