Chen Geng, Liang Hongsheng, Yun Jijun, Zhang Limin, Wu Hongjing, Wang Jianyuan
MOE Key Laboratory of Material Physics and Chemistry under Extraordinary, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an, 710072, P. R. China.
Adv Mater. 2023 Dec;35(49):e2305586. doi: 10.1002/adma.202305586. Epub 2023 Oct 27.
Ultrasonic field (USF) is widely used to regulate the intrinsic properties of materials that are not applied in electromagnetic wave (EMW) absorption. One reason is that the lack of a response mechanism for the materials to USF hinders the expansion of their EMW absorption performance. Therefore, to address this issue, a series of CuS nanoparticles with diverse anions are constructed in the presence or absence of USF. The ultrasonic-induced cavitation effect can significantly promote CuS crystallization and lead to the accumulation of S defects at the grain boundaries (GBs). Furthermore, the S defects at the GBs are easily oriented and arranged, allowing the polarization relaxation retention to be maintained at 10 wt%. Consequently, the CuS with a nitrate precursor under USF shows an optimum effective absorption bandwidth (EAB) of 10.24 GHz at a thickness of 3.5 mm, which is 228.6% more than that without the USF. CuS with a chloride precursor also achieves an EAB of 3.92 GHz, even at a considerably low filler ratio. Thus, this study demonstrates the response mechanism of diverse anions to the USF for the first time and provides a novel technique to optimize the EMW absorption performance of semiconductors.
超声场（USF）被广泛用于调节那些不应用于电磁波（EMW）吸收的材料的内在特性。一个原因是材料对USF缺乏响应机制阻碍了其EMW吸收性能的扩展。因此，为了解决这个问题，在有或没有USF的情况下构建了一系列具有不同阴离子的硫化铜纳米颗粒。超声诱导的空化效应可以显著促进硫化铜结晶并导致晶界（GBs）处硫缺陷的积累。此外，GBs处的硫缺陷易于取向和排列，使得极化弛豫保留率在10 wt%时得以维持。因此，在USF下具有硝酸盐前驱体的硫化铜在厚度为3.5 mm时显示出10.24 GHz的最佳有效吸收带宽（EAB），比没有USF时高出228.6%。具有氯化物前驱体的硫化铜即使在相当低的填料比下也能实现3.92 GHz的EAB。因此，本研究首次证明了不同阴离子对USF的响应机制，并提供了一种优化半导体EMW吸收性能的新技术。
