Schottky Heterojunction Engineering in Core–Shell SiC@Cu Nanowires for Ultra‐Broadband Electromagnetic Wave Absorption and Rapid Heat Dissipation

ABSTRACT The increasing miniaturization of electronic devices intensifies the challenges of electromagnetic interference and heat accumulation, demanding integrated solutions. Herein, a Schottky heterojunction engineering strategy is proposed through the rational design of one‐dimensional core–shell SiC@Cu nanowires. A continuous, highly thermally conductive Cu layer is uniformly coated onto n‐type SiC nanowires via electroless deposition, creating intimate Schottky interfaces. The significant work function difference between Cu and SiC generates a strong built‐in electric field (BIEF), which dramatically enhances interfacial polarization loss. Coupled with the large specific surface area provided by the high‐aspect‐ratio SiC core, this results in exceptional microwave dissipation. With a filling ratio of 20 wt.%, the SiC@Cu achieves a remarkable minimum reflection loss of −51 dB and an ultra‐broadband effective absorption bandwidth of 11.76 GHz, far surpassing the performance of bare SiC nanowire. Simultaneously, the conformal Cu shell establishes efficient heat conduction pathways, elevating the inter‐plane thermal conductivity to 0.317 W m ⁻¹ K ⁻¹ at a volume ratio of only 1%, approximately twice that of its SiC nanowire counterpart (0.147 W m ⁻¹ K ⁻¹ ). This work pioneers a novel heterojunction‐engineering approach for developing advanced multifunctional materials that concurrently manage electromagnetic and thermal energy.