In this paper, the growth of optimized vertically aligned multi-walled carbon nanotube (VA-MWCNT) forests by LPCVD method for use in a large-area absorber in infrared detectors is presented. The effect of synthesis temperature (500−700 °C) and time (1−10 min) on the optical absorption coefficient in the infrared (2−20 μm) is investigated by FT-IR measurement at various incident angles (15-80°). The structural properties of VA-MWCNT are characterized by SEM, TEM and Raman spectroscopy. Spectral measurements show an increasing absorption with the height of the forest that results at increased synthesis time and temperature. However, the absorption coefficient decreases with increasing synthesize time and temperature, while it is also affected by other properties, such as diameter, density, alignment, and uniformity. Moreover, the reduction in absorption at oblique incident angles demonstrates the relevance of surface properties. Finally, a circular graphite waveguide system is used to model the absorption characteristics of an MWCNT forest.

中文翻译：

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垂直排列的多壁碳纳米管林的红外吸收作为合成温度和时间的函数

在本文中，介绍了通过 LPCVD 方法生长优化的垂直排列的多壁碳纳米管 (VA-MWCNT) 林，用于红外探测器的大面积吸收器。通过在不同入射角 (15-80°) 下的 FT-IR 测量研究合成温度 (500-700 °C) 和时间 (1-10 分钟) 对红外 (2-20 μm) 光吸收系数的影响）。VA-MWCNT的结构特性通过SEM、TEM和拉曼光谱表征。光谱测量表明，随着合成时间和温度的增加，森林高度的吸收会增加。然而，吸收系数随着合成时间和温度的增加而降低，同时它还受其他特性的影响，如直径、密度、排列和均匀性。而且，斜入射角吸收的减少表明了表面特性的相关性。最后，圆形石墨波导系统用于模拟 MWCNT 森林的吸收特性。