Carbon Nanomaterial Devices for Infrared and Terahertz Technology

虽然用于操纵和检测电磁频谱的可见光和近红外范围内的光的技术已经取得了非凡的成功，但用于电磁频谱的中红外（MIR）和太赫兹（THz）范围的设备尚未达到成熟。扩大对这一频率范围的访问，为健康、能源、空间、通信、成像和传感领域的应用带来了希望。碳纳米材料具有独特的物理性质，这使它们成为MIR和THz范围内应用的合适候选者。根据碳纳米管的类型，它们强烈吸收从可见光到THz区域的整个频率范围内的光。人们可以通过选择特定的频率范围来为给定的应用选择碳纳米管的类型。石墨烯也在整个电磁光谱上吸收光，此外，可以通过施加栅极电压来调节MIR和THz范围内的吸收强度。石墨烯还具有高导电性，使其适合于高操作速度。这项研究的目标是开发用于检测和操纵MIR和THz区域中的光的设备，使用对齐的碳纳米管片，石墨烯，以及利用每种材料的最佳性能的两者的组合。技术描述：碳纳米材料如单壁碳纳米管（SWCNT）和石墨烯是具有电子、光子和磁性能，其适合于各种光电器件应用，特别是在技术上不太发达的中红外（MIR）和太赫兹（THz）光谱范围。根据手性，SWCNT强烈吸收整个电磁光谱的辐射。最近，使用SWCNT溶液的缓慢真空过滤已经开发了对齐的、密集堆积的和手性富集的SWCNT的晶片级膜的制造。这些膜在宏观取向的膜中保持了一维/各向异性SWCNT的非凡特性，将纳米材料的非凡特性带到了技术上有用的宏观尺度。例如，根据辐射相对于膜中纳米管排列的偏振，可以在宽频率范围内强烈吸收或完全透射入射辐射，包括MIR和THz区域。石墨烯也吸收整个电磁光谱中的光，但载流子密度可以通过静电门控来调节，以控制MIR和THz区域中的光吸收。此外，石墨烯的高导电性导致高操作速度。这项研究的目标是利用对齐的SWCNT薄膜，石墨烯以及这两种材料的组合，在MIR和THz范围内创建双曲超材料，光电探测器和调制器。

Although technologies for the manipulation and detection of light in the visible and near-infrared range of the electromagnetic spectrum have seen extraordinary success, devices for the mid-infrared (MIR) and terahertz (THz) range of the electromagnetic spectrum have yet to reach maturity. Expanding access to this frequency range holds promise for applications in the fields of health, energy, space, communications, imaging, and sensing. Carbon nanomaterials have unique physical properties, which make them suitable candidates for applications in the MIR and THz range. Depending on the type of carbon nanotubes, they strongly absorb light in the entire frequency range from the visible to the THz region. One can select the type of carbon nanotube for a given application by selecting for a particular frequency range. Graphene absorbs light over the entire electromagnetic spectrum as well, and furthermore, one can tune the strength of absorption in the MIR and THz range by applying a gate voltage. Graphene also has a high electrical conductivity, making it suitable for high operation speed. The goal of this research is to develop devices for the detection and manipulation of light in the MIR and THz region, using sheets of aligned carbon nanotubes, graphene, and a combination of the two utilizing the best properties of each material.Technical description:Carbon nanomaterials such as single-wall carbon nanotubes (SWCNTs) and graphene are low-dimensional materials with electronic, photonic, and magnetic properties that are suitable for a variety of optoelectronic device applications especially in the less technologically developed mid-infrared (MIR) and terahertz (THz) spectral ranges. Depending on chirality, SWCNTs strongly absorb radiation across the entire electromagnetic spectrum. Recently, the fabrication of wafer-scale films of aligned, densely packed, and chirality-enriched SWCNTs has been developed using slow vacuum filtration of SWCNT solution. These films maintain the extraordinary properties of one-dimensional/anisotropic SWCNTs in a macroscopically aligned film, bringing the extraordinary properties of the nanomaterial to a technologically useful macroscopic scale. For instance, depending on the polarization of radiation with respect to the nanotube alignment in the film, one can strongly absorb or completely transmit incident radiation over a broad frequency range, including the MIR and THz regions. Graphene also absorbs light in the entire electromagnetic spectrum, but the carrier density can be tuned by electrostatic gating to control the absorption of light in the MIR and THz regions. Furthermore, the high electrical conductivity of graphene leads to high operation speed. The goal of this research is to create hyperbolic metamaterials, photodetectors, and modulators in the MIR and THz range, utilizing aligned SWCNT films, graphene, and a combination of the two materials.