Keith Roper D
Utah State University, Logan, UT 84322 USA.
IEEE Nanotechnol Mater Devices Conf. 2024 Oct;2024:123-128. doi: 10.1109/nmdc58214.2024.10894700. Epub 2025 Feb 25.
Extinction in thin polymer films containing nanoparticles is important to photovoltaics, sensors, and interconnects. Extinction measured in 1-millimeter-thin films containing plasmonic nanoparticles increased with nanoparticle density to levels higher than predicted. Yet, enhancement of extinction was not measured in <100-nanometer-thin films containing high-density plasmonic nanoparticles. The present study examined extinction in 80 micrometer films that contained plasmonic nanoparticles at increasing volume fractions. Optical images and spectra were integrated in a new hyperspectral method to quantitate visual attributes to use nanoparticle-containing films in e.g., colorimetric assays. Measured extinction was compared with values predicted by the exact Mie solution to Maxwell's equation and by the Maxwell-Garnett effective medium theory. Extinction measured in 80-micron films was found to increase with nanoparticle volume fraction from a low value predicted by Mie theory to a high value predicted by Maxwell-Garnett effective medium theory. Results of the present study are useful to specify the volume fraction of nanoparticles in thin polymer films to obtain desired spectral characteristics for photovoltaics, sensors, interconnects, and colorimetric point-of-care assays.
含纳米颗粒的聚合物薄膜中的消光对光伏、传感器和互连技术而言至关重要。在含有等离子体纳米颗粒的1毫米厚薄膜中测得的消光随纳米颗粒密度增加，达到高于预测的水平。然而，在含有高密度等离子体纳米颗粒的<100纳米厚薄膜中未测得消光增强。本研究检测了含有不同体积分数等离子体纳米颗粒的80微米薄膜中的消光情况。光学图像和光谱通过一种新的高光谱方法进行整合，以量化视觉属性，从而将含纳米颗粒的薄膜用于例如比色测定中。将测得的消光与通过麦克斯韦方程的精确米氏解以及麦克斯韦 - 加尼特有效介质理论预测的值进行比较。发现在80微米薄膜中测得的消光随纳米颗粒体积分数增加，从米氏理论预测的低值增加到麦克斯韦 - 加尼特有效介质理论预测的高值。本研究结果有助于确定聚合物薄膜中纳米颗粒的体积分数，以获得光伏、传感器、互连技术和比色即时检测所需的光谱特性。
