Ren Zhiyu, Niu Sijia, Gao Haixiang, Wang Chenchong, Liu Xiaoming, Wang Kai, Wang Qiang
Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, Shenyang, 110819, China.
School of Metallurgy, Northeastern University, Shenyang, 110819, China.
Small. 2025 Jun;21(23):e2501698. doi: 10.1002/smll.202501698. Epub 2025 Apr 27.
Efficient utilization of solar energy is crucial in addressing energy challenges. Solar selective absorption materials, like metal-insulator-metal (MIM) absorbers, are highly efficient in converting solar energy to heat due to their strong solar absorption and minimal radiation loss. However, traditional planar MIM absorbers have narrow solar absorption bands and limited spectral tuning, restricting their practical use. Inspired by marine diatoms, this study designs and fabricates a structured MIM metamaterial (SMM) to achieve omnidirectional and polarization-insensitive selective absorption. The SMM features a concave-structured design with gradient resonance cavities, significantly expanding absorption across the solar spectrum and enabling tailored electromagnetic responses for selective absorption in different wavelength bands. With a thickness of just 180 nm, the SMM absorber shows outstanding selective absorption, reaching up to 91% absorptivity in the 0.3-2.5 µm and emissivity only 0.09 in the infrared range. The SMM absorber also exhibits size insensitivity, reducing design constraints in practical applications. In terms of photothermal conversion, the SMM absorber demonstrates stable performance, achieving a surface temperature of 165 °C under 3 sun illumination. Compared to planar MIM structures, this structured design significantly enhances solar absorption without affecting infrared emissivity, offering a novel approach to improving selective absorption performance.
高效利用太阳能对于应对能源挑战至关重要。太阳能选择性吸收材料，如金属-绝缘体-金属（MIM）吸收器，由于其强烈的太阳能吸收和最小的辐射损失，在将太阳能转化为热能方面具有很高的效率。然而，传统的平面MIM吸收器具有狭窄的太阳能吸收带和有限的光谱调谐能力，限制了它们的实际应用。受海洋硅藻的启发，本研究设计并制造了一种结构化MIM超材料（SMM），以实现全向和偏振不敏感的选择性吸收。SMM具有带有梯度共振腔的凹面结构设计，显著扩展了整个太阳光谱的吸收范围，并能够针对不同波段的选择性吸收进行定制电磁响应。SMM吸收器厚度仅为180纳米，显示出出色的选择性吸收，在0.3-2.5微米范围内吸收率高达91%，在红外范围内发射率仅为0.09。SMM吸收器还表现出尺寸不敏感性，减少了实际应用中的设计限制。在光热转换方面，SMM吸收器表现出稳定的性能，在3倍太阳光照下表面温度达到165°C。与平面MIM结构相比，这种结构化设计在不影响红外发射率 的情况下显著增强了太阳能吸收，为提高选择性吸收性能提供了一种新方法。
