Ultra‐Broadband Wide‐Angle Terahertz Absorption Properties of 3D Graphene Foam

Huang, Zhiyu; Chen, Honghui; Huang, Yi; Ge, Zhen; Zhou, Ying; Yang, Yang; Xiao, Peishuang; Liang, Jiajie; Zhang, Tengfei; Shi, Qian; Li, Guanghao; Chen, Yongsheng

doi:10.1002/adfm.201704363

Cited by 262 publications

(147 citation statements)

References 47 publications

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“…When the annealing temperature is 600 °C, I D / I G = 1.62. As an ultralight material, the density of the GF of 600 °C annealing temperature is only 1 mg cm −3 . According to previous research, for samples annealed in the range between 600 and 800 °C, its Fermi level ( E F ) crosses the bandgap, the free carriers change from hole to electrons, and the free carrier density is in the lowest state .…”

Section: Resultsmentioning

confidence: 98%

“…For example, Zdrojek et al demonstrated a graphene‐based plastic absorber, and more than 99.99% of the electromagnetic energy is shielded via absorption in the sub‐THz range. The porous materials have a better shielding performance for their larger porosity . For instance, our previous work reported the multiwalled carbon nanotubes doped 3D graphene foam (GF), which has both excellent THz shielding and stealth performance in the THz regime.…”

Section: Introductionmentioning

confidence: 99%

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Active Terahertz Shielding and Absorption Based on Graphene Foam Modulated by Electric and Optical Field Excitation

Fan

Cheng

et al. 2019

Advanced Optical Materials

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Ultralight materials for broadband terahertz (THz) shielding and absorption are promising in practical THz applications. Here, active THz shielding and absorption properties of 3D graphene foam (GF) controlled by both laser pumping and biased electric field are investigated. The GF can be tuned from OFF‐shielding state to ON‐shielding state when the external field excitations are applied, and 10 dB shielding bandwidth expands from 0 to a broad band of 0.2–1.6 THz. Further researches show that the GF always keeps very low THz reflection either with or without external fields, but its absorption characteristics can be remarkably controlled from 13% to 95.4% at 0.3 THz by the power of the external excitations, and its specific average terahertz absorption performance increases from 3.9 × 103 to 1.95 × 104 dB cm3 g−1. This modulation mechanism reveals that the carrier density in GF increases one order of magnitude from 2.6 × 1014 cm−3 to 3.15 × 1015 cm−3. Finally, the tunable THz shielding and absorption characteristics of this GF device are demonstrated by THz transmission imaging, which shows its great potential applications in active THz imaging, radar, and electromagnetic compatibility.

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Section: Resultsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Active Terahertz Shielding and Absorption Based on Graphene Foam Modulated by Electric and Optical Field Excitation

Fan

Cheng

et al. 2019

Advanced Optical Materials

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“…Remarkably, the absorbance dominates over the reflectance a lot over for GF and MGF samples in free air. Obviously, the highly porous structure contributes to the ultralow terahertz reflection and also facilitates stronger absorption attenuation due to more interfaces for multiple reflection and scattering …”

Section: Resultsmentioning

confidence: 99%

“…Up till now, stealth materials with porous structures have been often reported in the microwave regime . Recently, our group has been the first to achieve a highly efficient and porous absorber in the terahertz region . However, research on porous terahertz stealth materials is just beginning, and still faces many problems and challenges.…”

Section: Introductionmentioning

confidence: 99%

Graphene‐Based Composites Combining Both Excellent Terahertz Shielding and Stealth Performance

Huang

Chen

et al. 2018

Advanced Optical Materials

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terahertz imaging, [9][10][11] terahertz detection, [12][13][14] and so on, terahertz related circuits and electronic components have been widely applied to current technologies. The fast-growing applications for terahertz waves have led to an urgent demand for terahertz shielding materials in order to effectively reduce the interference of terahertz wave signals, improve their transmission environment, and ensure that the delicate electronic instruments work as normal. Moreover, terahertz stealth materials also play a very important role in the fields of national security and information protection, which may help to avoid significant losses to individuals, enterprises, and even countries. Therefore, high-performance terahertz shielding/stealth materials have the potential for wide applications. [15] Traditional terahertz shielding materials are mainly composed of reflective materials because they reflect the incident terahertz wave by simply increasing conductivity. [16,17] For example, it is reported that a terahertz-shielding membrane prepared by a pyrolysis process for commercial polyimide has a very high reflectivity of more than 90%. [18] However, reflective shielding materials have two fatal flaws. First, reflective shielding materials cannot completely eliminate the interference of terahertz waves, because the reflected terahertz wave still adversely affects other sophisticated electronic elements inside the shielded devices. [19] Second, reflective shielding materials usually have a large density. The reflective Strong terahertz-response material which exhibits both excellent terahertz shielding and stealth performance is promising in practical applications of terahertz technology. Here, ultralight graphene foam (GF) and multiwalled carbon nanotubes/multiwalled graphene foam (MGF) have been first demonstrated to achieve both superior terahertz shielding and stealth performance due to the dominant absorption loss with negligible reflection. The terahertz shielding effectiveness values of GF and MGF, both 3 mm thick, reach up to 74 and 61 dB. Meanwhile, their average terahertz reflection loss values are achieved up to 23 and 30 dB, respectively, which are the best results in existing broadband terahertz shielding/stealth materials. Importantly, their qualified absorption bandwidths (reflection loss value larger than 10 dB) cover the entire measured frequency band of 0.1-1.6 THz. Furthermore, the quantitative relationships between the terahertz shielding effectiveness, reflection loss, and material parameters are accurately established, which should facilitate the material design for terahertz shielding and stealth. Comprehensively considering the important indicators of density, bandwidth, and intensity, the specific average terahertz shielding coefficient and the specific average terahertz absorption performance are achieved up to 1.1 × 10 5 and 3.6 × 10 4 dB cm 3 g −1 , respectively, which is over thousands of times larger than other kinds of materials reported previously. Shielding/Stealth MaterialsThe...

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“…The rapid development of electronic technologies brings about great convenience to humans' life. However, excessive usage of electronics also results in serious electromagnetic (EM) radiation and interference, which is detrimental to human health [1][2][3][4][5]. Consequently, the research on use of functional EM absorbers to eliminate the unwanted EM energies has attracted significant attention.…”

Section: Introductionmentioning

confidence: 99%

Biomass-Derived Porous Carbon-Based Nanostructures for Microwave Absorption

et al. 2019

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HIGHLIGHTS• The synthetic methods and corresponding mechanisms of porous carbon (PC)-based nanostructures from biomass resource are reviewed.• The application of biomass-derived PC in microwave absorption is discussed in terms of structure and composition optimization.ABSTRACT Currently, electromagnetic (EM) pollution poses severe complication toward the operation of electronic devices and biological systems. To this end, it is pertinent to develop novel microwave absorbers through compositional and structural design. Porous carbon (PC) materials demonstrate great potential in EM wave absorption due to their ultralow density, large surface area, and excellent dielectric loss ability. However, the large-scale production of PC materials through low-cost and simple synthetic route is a challenge. Deriving PC materials through biomass sources is a sustainable, ubiquitous, and low-cost method, which comes with many desired features, such as hierarchical texture, periodic pattern, and some unique nanoarchitecture. Using the bio-inspired microstructure to manufacture PC materials in mild condition is desirable. In this review, we summarize the EM wave absorption application of biomass-derived PC materials from optimizing structure and designing composition. The corresponding synthetic mechanisms and development prospects are discussed as well. The perspective in this field is given at the end of the article.

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Ultra‐Broadband Wide‐Angle Terahertz Absorption Properties of 3D Graphene Foam

Cited by 262 publications

References 47 publications

Active Terahertz Shielding and Absorption Based on Graphene Foam Modulated by Electric and Optical Field Excitation

Active Terahertz Shielding and Absorption Based on Graphene Foam Modulated by Electric and Optical Field Excitation

Graphene‐Based Composites Combining Both Excellent Terahertz Shielding and Stealth Performance

Biomass-Derived Porous Carbon-Based Nanostructures for Microwave Absorption

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