Vertically aligned carbon nanotube (VACNT) arrays have been explored as an absorber of thermal-type photodetectors. A long and dense VACNT array absorbs a wide spectral range of incident light with high absorption rate, but has a high thermal mass that results in a low response speed. To achieve a small thermal mass, a shorter and less dense VACNT array is needed. In addition, the high temperature needed to grow the VACNTs is detrimental to the functional sensing materials of the photodetector. The height, density, and growth temperature of VACNTs need to be optimized to achieve a working absorber that has high absorption rate and a high response speed. In this work, a low-temperature plasma enhanced chemical vapor deposition process is used to prepare various VACNT arrays with different heights and densities by controlling the CNT growth parameters. The absorption coefficients of the resulting samples are measured with Fourier transform infrared spectroscopy. An effective medium theory (EMT) is adopted to establish a working model of the VACNTs. Using experimentally extracted CNT density and height as fitting parameters, the EMT model is fitted to obtain theoretical absorption coefficients, which are found to be comparable to the experimentally measured absorption coefficients. Our experimental and theoretical investigations pave the way for future studies to integrate CNTs with infrared photodetectors.

垂直排列的碳纳米管 (VACNT) 阵列已被探索作为热型光电探测器的吸收器。长而密集的 VACNT 阵列以高吸收率吸收宽光谱范围的入射光，但具有高热质量，导致响应速度低。为了获得较小的热质量，需要更短且密度更低的 VACNT 阵列。此外，生长 VACNT 所需的高温不利于光电探测器的功能传感材料。需要优化 VACNT 的高度、密度和生长温度，以实现具有高吸收率和高响应速度的工作吸收体。在这项工作中，通过控制CNT生长参数，采用低温等离子体增强化学气相沉积工艺制备具有不同高度和密度的各种VACNT阵列。用傅立叶变换红外光谱测量所得样品的吸收系数。采用有效介质理论（EMT）建立了 VACNT 的工作模型。使用实验提取的 CNT 密度和高度作为拟合参数，拟合 EMT 模型以获得理论吸收系数，发现其与实验测量的吸收系数相当。我们的实验和理论研究为未来将碳纳米管与红外光电探测器集成的研究铺平了道路。用傅立叶变换红外光谱测量所得样品的吸收系数。采用有效介质理论（EMT）建立了 VACNT 的工作模型。使用实验提取的 CNT 密度和高度作为拟合参数，拟合 EMT 模型以获得理论吸收系数，发现其与实验测量的吸收系数相当。我们的实验和理论研究为未来将碳纳米管与红外光电探测器集成的研究铺平了道路。用傅立叶变换红外光谱测量所得样品的吸收系数。采用有效介质理论（EMT）建立了 VACNT 的工作模型。使用实验提取的 CNT 密度和高度作为拟合参数，拟合 EMT 模型以获得理论吸收系数，发现其与实验测量的吸收系数相当。我们的实验和理论研究为未来将碳纳米管与红外光电探测器集成的研究铺平了道路。发现它们与实验测量的吸收系数相当。我们的实验和理论研究为未来将碳纳米管与红外光电探测器集成的研究铺平了道路。发现它们与实验测量的吸收系数相当。我们的实验和理论研究为未来将碳纳米管与红外光电探测器集成的研究铺平了道路。