Ultrathin, lightweight, and flexible electromagnetic interference (EMI) shielding materials are urgently demanded to address EM radiation pollution. Efficient design to utilize the shields' microstructures is crucial yet remains highly challenging for maximum EMI shielding effectiveness (SE) while minimizing material consumption. Herein, novel cellular membranes are designed based on a facile polydopamine‐assisted metal (copper or silver) deposition on electrospun polymer nanofibers. The membranes can efficiently exploit the high‐conjunction cellular structures of metal and polymer nanofibers, and their interactions for excellent electrical conductivity, mechanical flexibility, and ultrahigh EMI shielding performance. EMI SE reaches more than 53 dB in an ultra‐broadband frequency range at a membrane thickness of merely 2.5 µm and a density of 1.6 g cm−3, and an SE of 44.7 dB is accomplished at the lowest thickness of 1.2 µm. The normalized specific SE is up to 232 860 dB cm2 g−1, significantly surpassing that of other shielding materials ever reported. More, integrated functionalities are discovered in the membrane, such as antibacterial, waterproof properties, excellent air permeability, high resistance to mechanical deformations and low‐voltage uniform heating performance, offering strong potential for applications in aerospace and portable and wearable smart electronics.

Nanowire memristor devices that display multilevel memory effects are of great interest for high‐density storage, however, numerous challenges remain in fabricating high‐quality, stable memory units. A plasmonic‐radiation‐enhanced technique is introduced in this work for scalably forming nanowire multilevel memory units with superior properties. Femtosecond laser irradiation of gold‐titanium dioxide nanowire‐gold structures results in plasmonic‐enhanced optical absorption in the TiO2 locally at the metal‐oxide interface. This produces junctions with superior mechanical and electrical contact, and engineers a concentration of charged defects in the TiO2 near the interface, which enables stable multilevel memory behavior without the need for a traditional electroforming step. The memory units produced display eight‐level current amplification under continuous forward voltage cycles, and can replicate complex multilevel memory sequences without interference between the different multilevel states.

A comprehensive understanding of the oxidation of Cu thin films in the low-temperature regime is of fundamental interest and particularly relevant for applications in the fields of micro-and nanoelectronics, sensors, catalysis, and solar cells. The current study reports on the oxidation kinetics of PVD grown Cu thin films (20-150 nm thick) and the oxide phase evolution from Cu 2 O to CuO upon thermal oxidation in the temperature range of 100-450°C. XRD investigations in the laboratory and at the synchrotron show that the oxide phase formation critically depends on the oxidation conditions such as temperature and oxygen partial pressure. The real-time synchrotron XRD measurements reveal that the formation of the CuO phase only starts after complete oxidation of the Cu films to Cu 2 O films. In situ resistance measurements were performed to follow the oxide growth rate of Cu 2 O on Cu films in the temperature range of 100-300°C in air and in 10 mbar pO 2 . It is found that the oxidation kinetics of Cu films to Cu 2 O films follows the linear rate law, which is attributed to surface reaction controlled oxidation. The oxygen dissociation rate at the gas-solid interface is the rate-limiting process. A dramatic decrease in the linear oxidation rate is observed at low oxygen partial pressures. The fundamental differences between the oxidation rate-limiting processes of Cu as compared to other transition metal films are discussed.

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We report the in situ joining of spatially separated silver nanowires without additional filler material by controlled irradiation with femtosecond laser pulses. Nanojoining under these conditions arises from highly localized heat generation in the vicinity of the gap between adjacent silver nanowires. Melting, followed by the flow of silver into the gap, is optimized by adjusting the direction of laser polarization relative to gap geometry. Our results show that melting of silver occurs on both nanowires in the vicinity of the gap between the two components. Successful formation of a joint is found to be a function of the angle between the long axis of the nanowires and the gap distance. Finite element simulations show that the strong localized electric field generated by optical excitation determines the location and the morphology of the resulting bond. Light coupling and the resulting emission properties of these Y-shaped nanowire structures have been simulated and are compared to similar structures where the gap remains open. It is suggested that joined Y-shaped couplers will have a higher switching ratio between emitted nanowire ends than those occurring in open-gap structures. Nanojoining induced by localized heating under strong field excitation may enable the production of robust branched metal nanowire structures for optical applications.