Gong Tao, Lyu Peifen, Leite Marina S
Department of Materials Science and Engineering, University of California, Davis, Davis, California 95616, United States.
Department of Electrical and Computer Engineering, University of California, Davis, Davis, California 95616, United States.
ACS Appl Opt Mater. 2023 Jan 31;1(4):825-831. doi: 10.1021/acsaom.2c00159. eCollection 2023 Apr 28.
Optical materials based on unconventional plasmonic metals (e.g., magnesium) have lately driven rising research interest for the quest of possibilities in nanophotonic applications. Several favorable attributes of Mg, such as earth abundancy, lightweight, biocompatibility/biodegradability, and its active reactions with water or hydrogen, have underpinned its emergence as an alternative nanophotonic material. Here, we experimentally demonstrate a thin film-based optical device composed exclusively of earth-abundant and complementary metal-oxide semiconductor (CMOS)-compatible materials (i.e., Mg, a-Si, and SiO). The devices can exhibit a spectrally selective and tunable near-unity resonant absorption with an ultrathin a-Si absorbing layer due to the strong interference effect in this high-index and lossy film. Alternatively, they can generate diverse reflective colors by appropriate tuning of the a-Si and SiO layer thicknesses, including all the primary colors for RGB (red, green, blue) and CMY (cyan, magenta, yellow) color spaces. In addition, the reflective hues of the devices can be notably altered in a zero power-consumption fashion by immersing them in water due to the resulted dissolution of the Mg back-reflection layer. These compelling features in combination with the lithography-free and scalable fabrication steps may promise their adoption in various photonic applications including solar energy harvesting, optical information security, optical modulation, and filtering as well as structure reuse and recycling.
基于非常规等离子体金属（如镁）的光学材料最近引发了越来越多的研究兴趣，以探索其在纳米光子学应用中的可能性。镁的几个有利特性，如在地壳中储量丰富、重量轻、生物相容性/生物可降解性以及它与水或氢的活性反应，使其成为一种替代的纳米光子材料。在此，我们通过实验展示了一种仅由地壳中储量丰富且与互补金属氧化物半导体（CMOS）兼容的材料（即镁、非晶硅和二氧化硅）组成的薄膜光学器件。由于在这种高折射率且有损耗的薄膜中存在强烈的干涉效应，该器件能够通过超薄的非晶硅吸收层表现出光谱选择性且可调谐的接近单位的共振吸收。或者，通过适当调整非晶硅和二氧化硅层的厚度，它们可以产生多种反射颜色，包括RGB（红、绿、蓝）和CMY（青、品红、黄）颜色空间的所有原色。此外，由于镁背反射层的溶解，将器件浸入水中可以以零功耗的方式显著改变器件的反射色调。这些引人注目的特性与无需光刻且可扩展的制造步骤相结合，可能使其在包括太阳能收集、光学信息安全、光调制和滤波以及结构再利用和回收等各种光子学应用中得到应用。
