Creating porous structures and gradient structures are two commonly used design strategies for terahertz (THz) absorption enhancement. However, the synergistic effect of porous structure and gradient structure on THz absorption still remains less explored. Here, we took an almost non-conductive porous carbon foam as raw material, and fabricated an integrated gradient porous carbon foam (PCF) by microwave selective sintering. The experimental results show that the synergistic effect of the porous and gradient structures resulted in a 140% improvement in THz absorption performance. Specifically, an excellent average absorption intensity of −38.8 dB (absorptivity is about 99.99%) is obtained in the frequency range from 0.5 to 4.0 THz. COMSOL simulation and transmission line model were applied to explore the formation mechanism and the gradient loss capabilities of gradient structure. This work not only reveals the synergistic enhancement mechanism of porous and gradient structures for the THz absorption, but also provides new insights into the design of high-performance THz absorbers in the future.

中文翻译：

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碳泡沫中多孔结构和梯度结构的协同效应促进太赫兹吸收


创建多孔结构和梯度结构是太赫兹（THz）吸收增强的两种常用设计策略。然而，多孔结构和梯度结构对太赫兹吸收的协同效应仍然鲜有研究。在这里，我们以几乎不导电的多孔碳泡沫为原料，通过微波选择性烧结制备了集成梯度多孔碳泡沫（PCF）。实验结果表明，多孔结构和梯度结构的协同作用使太赫兹吸收性能提高了140%。具体而言，在0.5至4.0THz的频率范围内获得了-38.8dB的优异平均吸收强度（吸收率约为99.99%）。应用COMSOL仿真和传输线模型探索梯度结构的形成机制和梯度损失能力。这项工作不仅揭示了多孔和梯度结构对太赫兹吸收的协同增强机制，而且为未来高性能太赫兹吸收体的设计提供了新的见解。