ABSTRACT

While anti-reflective properties of pyramid texture are widely used, their use for thermal radiation control has received relatively little attention and the understanding of geometric parameters for design optimization is not well established. Here we use finite-difference time-domain simulations in conjunction with an algorithm to optimize thermal characteristics of micropyramid-textured metallic, ceramic, and polymer materials. Our simulations indicate that the pyramid height-to-base ratio is an effective parameter in developing an engineered thermal response. For nickel, the micropyramids with 2–4 height-to-base ratios over 0.5–4 µm base spans provide near-perfect absorption in 300–2500 nm wavelengths. The electric field analysis shows the optical properties are driven by the effects of localized resonance and field confinement. Our thermal cost function-based optimization has led to micropyramid texture that can have a significant impact on heating or cooling such as the solar absorption increase in nickel from 337 to 982 W/m², the thermal emission increase in alumina from 106 to 170 W/m², and the thermal emission increase in PDMS from 160 to 172 W/m². This work not only provides the understanding of micropyramid properties for thermal radiation control but also presents an algorithmic process that could be used for efficient optical-thermal optimization of geometries beyond micropyramids.

摘要

虽然金字塔纹理的抗反射特性被广泛使用，但它们用于热辐射控制的关注相对较少，并且对用于设计优化的几何参数的理解还没有很好地建立。在这里，我们结合使用有限差分时域模拟和算法来优化微金字塔纹理金属、陶瓷和聚合物材料的热特性。我们的模拟表明，金字塔的高底比是开发工程热响应的有效参数。对于镍，在 0.5–4 µm 基跨度上具有 2–4 高基比的微金字塔在 300–2500 nm 波长提供近乎完美的吸收。电场分析表明光学特性受局部共振和场限制的影响。^{如图2所示}，氧化铝的热辐射从106增加到170 W/m ²，而PDMS的热辐射从160增加到172 W/m ²。这项工作不仅提供了对热辐射控制的微金字塔特性的理解，而且还提出了一种算法过程，可用于对微金字塔以外的几何进行有效的光热优化。