材料科学
电介质
微波食品加热
半导体
介电损耗
光电子学
极化(电化学)
衰减
反射损耗
散射
光学
复合材料
化学
电信
物理
物理化学
复合数
计算机科学
作者
Zhe Su,Shan Yi,Wanyu Zhang,Xiaxi Xu,Yayun Zhang,Shenghu Zhou,Bo Niu,Donghui Long
标识
DOI:10.1007/s40820-023-01151-0
摘要
Abstract The integration of nano-semiconductors into electromagnetic wave absorption materials is a highly desirable strategy for intensifying dielectric polarization loss; achieving high-attenuation microwave absorption and realizing in-depth comprehension of dielectric loss mechanisms remain challenges. Herein, ultrafine oxygen vacancy-rich Nb 2 O 5 semiconductors are confined in carbon nanosheets (ov-Nb 2 O 5 /CNS) to boost dielectric polarization and achieve high attenuation. The polarization relaxation, electromagnetic response, and impedance matching of the ov-Nb 2 O 5 /CNS are significantly facilitated by the Nb 2 O 5 semiconductors with rich oxygen vacancies, which consequently realizes an extremely high attenuation performance of − 80.8 dB (> 99.999999% wave absorption) at 2.76 mm. As a dielectric polarization center, abundant Nb 2 O 5 –carbon heterointerfaces can intensify interfacial polarization loss to strengthen dielectric polarization, and the presence of oxygen vacancies endows Nb 2 O 5 semiconductors with abundant charge separation sites to reinforce electric dipole polarization. Moreover, the three-dimensional reconstruction of the absorber using microcomputer tomography technology provides insight into the intensification of the unique lamellar morphology regarding multiple reflection and scattering dissipation characteristics. Additionally, ov-Nb 2 O 5 /CNS demonstrates excellent application potential by curing into a microwave-absorbing, machinable, and heat-dissipating plate. This work provides insight into the dielectric polarization loss mechanisms of nano-semiconductor/carbon composites and inspires the design of high-performance microwave absorption materials.
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