Terahertz narrowband perfect metasurface absorber based on micro-ring-shaped GaAs array for enhanced refractive index sensing

Li Z., Cheng Y., Luo H., Chen F., Li X.

A dual-band terahertz (THz) perfect absorber (PA) based on the all-dielectric metamaterial (MM) composed of the vertical-square-split-ring (VSSR) structure InSb array was proposed and investigated numerically. Simulation results show that the absorbance of the proposed PA under room temperature T = 295 K is up to 99.9% and 99.8% at 1.265 THz and 1.436 THz, respectively, which is consistent well with the fitting results of coupling mode theory (CMT). According to the simulated electric field and power loss density distributions, the perfect absorption results from the excitation of the first- and second-order plasmonic resonance mode. Further results show that the designed PA is polarization-insensitive due to the high geometric rotational symmetry, and wide-angle absorption can be achieved for transverse magnetic (TM) waves. The geometric parameters of the VSSR structure InSb and the external environment temperature can be changed to adjust the resonance absorption properties of the designed dual-band PA. The dual-band PA can be functional as a temperature sensor with a sensitivity of about 5.9 GHz/K and 6.4 GHz/K, respectively. Furthermore, the dual-band PA under T = 295 K also can be served as a refractive index sensor with a sensitivity of about 1.3 THz/RIU and 1.0 THz/RIU, respectively. Due to its excellent properties including simple design, easy fabrication, polarization-insensitive and perfect absorption, the proposed dual-band PA may find many potential applications in detecting, imaging, and sensing in the THz region. • Dual-band tunable perfect absorber (PA) based on InSb structure was proposed in THz region. • The absorbance of PA is up to 99.9% and 99.8% at 1.265 THz and 1.436 THz, respectively. • Perfect absorption due to the first- and second-order plasmonic resonance mode in the InSb structure. • The dual-band PA can be served as temperature sensor with sensitivity 5.9 GHz/K and 6.4 GHz/K, and refractive index (RI) sensor with a sensitivity 1.3 THz/RIU and 1.0 THz/RIU, respectively.

Zhao J., Cheng Y.

A temperature-tunable terahertz (THz) perfect absorber (PA) composed of a periodic array of deep subwavelength micro-cross-shaped (MCS) structures of the strontium titanate (STO) resonator is proposed and investigated theoretically, which can be applicable for the temperature sensing. Simulation results indicate that the absorbance of 99.8% at 0.221 THz can be achieved when the designed PA is under the room temperature of T = 300 K, which is in good agreement with the calculation done by the coupling mode theory (CMT). The simulated distributions of electric and magnetic fields in the unit-cell structure of the designed PA reveal that the observed perfect absorption is mainly attributed to the Mie resonance of the all-dielectric MCS structure STO. In addition, this designed PA is polarization-insensitive and wide-angle absorption for both transverse magnetic (TM) and transverse electric (TE) waves. The resonance absorption properties of the designed PA can be controlled by changing the geometrical parameters of STO resonator structure. The designed PA can be served as a temperature sensor, which has a sensitivity of about 0.37 GHz K−1 since the electrical property of the STO is dependent on the variation of surrounding temperature. Furthermore, the perfect absorption can also be achieved by the PAs using the square, circular, and ring STO structures. The proposed design concepts of the STO-based tunable PAs can find potential THz applications in sensing, detecting, imaging, and so on.

Cheng Y., Zhao J.

Abstract In this paper, we present a simple design of six-band terahertz (THz) perfect metasurface absorber (PMSA) composed of a single circular-split-ring (CSR) structure placed over a ground-plane by a dielectric substrate. The average absorbance of 99.1% at six distinct frequencies can be obtained for the proposed PMSA under normal incident THz wave. The distribution characteristics of electric field reveal that the six absorption peaks of the proposed PMSA mainly originate from the combination of the higher-order localized surface plasmon (LSP) and propagating surface plasmon (PSP) resonance modes. Moreover, the influences of geometric parameters on the resonance absorption properties of PMSA were investigated numerically. Owing to its excellent properties, this design of the six-band PMSA may have potential applications in imaging, sensing and detection.

Chen H., Chen Z., Yang H., Wen L., Yi Z., Zhou Z., Dai B., Zhang J., Wu X., Wu P.

In this paper, a multi-mode surface plasmon resonance absorber based on dart-type single-layer graphene is proposed, which has the advantages of polarization independence, tunability, high sensitivity, high figure of merit, etc. The device consists of a top layer dart-like patterned single-layer graphene array, a thicker silicon dioxide spacer layer and a metal reflector layer, and has simple structural characteristics. The numerical results show that the device achieves the perfect polarization-independent absorption at the resonance wavelengths of λI = 3369.55 nm, λII = 3508.35 nm, λIII = 3689.09 nm and λIV = 4257.72 nm, with the absorption efficiencies of 99.78%, 99.40%, 99.04% and 99.91%, respectively. The absorption effect of the absorber can be effectively regulated and controlled by adjusting the numerical values such as the geometric parameters and the structural period p of the single-layer graphene array. In addition, by controlling the chemical potential and the relaxation time of the graphene layer, the resonant wavelength and the absorption efficiency of the mode can be dynamically tuned. And can keep high absorption in a wide incident angle range of 0° to 50°. At last, we exposed the structure to different environmental refractive indices, and obtained the corresponding maximum sensitivities in four resonance modes, which are SI = 635.75 nm RIU-1, SII = 695.13 nm RIU-1, SIII = 775.38 nm RIU-1 and SIV = 839.39 nm RIU-1. Maximum figure of merit are 54.03 RIU-1, 51.49 RIU-1, 43.56 RIU-1, and 52.14 RIU-1, respectively. Therefore, this study has provided a new inspiration for the design of the graphene-based tunable multi-band perfect metamaterial absorber, which can be applied to the fields such as photodetectors and chemical sensors.

Shen Q., Xiong H.

• The absorber can be controlled by Fermi energy level ( E F ) and temperature ( T ). • Coupled-mode theory (CMT), perturbation theory, and the electric field distribution at the resonance point are utilized to verify the authenticity of numerical results. A perfect terahertz (THz) metamaterial absorber (MMA) based on bulk Dirac semimetal (BDS) and strontium titanate (STO) is proposed and numerically analyzed. By integrating two new materials with adjustable dielectric constant in one structure, the performance of this design can be flexibly controlled. The simulation results show that as the Fermi energy ( E F ) of BDS varies from 10 meV to 70 meV, the absorption rate can be tuned from 89% to 100%, with the resonant frequency exhibits a tiny blue shift. Meanwhile, the center frequency can be tuned by varying the temperature of STO from 150 K to 300 K. In addition, the absorption reaches 1 at 0.69 THz when the temperature of STO and E F of BDS are set as 200 K and 30 meV, respectively. The coupled-mode theory (CMT) and perturbation theory are used to explore the reason of perfect absorption and frequency tunable mechanism, respectively. Further research and analysis prove that this designed absorber shows outstanding feature of angular insensitivity. Our work provides a potential guide for designing multifunctional THz devices, such as photodetectors, modulators, sensors, and so on.

Zheng Z., Zheng Y., Luo Y., Yi Z., Zhang J., Liu Z., Yang W., Yu Y., Wu X., Wu P.

Terahertz functional devices have been instrumental in the development of terahertz technology. Moreover, the advent of metamaterials has greatly contributed to the advancement of terahertz devices. However, most of today's metamaterials in the terahertz band exhibit poor performance and are mono-functional. This greatly limits the scalability and application potential of the devices. To achieve diversification and tunability of device functionality, we propose a combination of metamaterial structures and vanadium dioxide film. A metamaterial absorber based on the thermotropic phase change material VO2 has been designed. Flexible switching of absorption performance (complete reflection and ultra-broadband perfect absorption) can be achieved through temperature adjustment. Moreover, the perfectly absorbed bandwidth is a staggering 3.3 THz. The thermal tuning of spectral absorbance has a maximal range of 0.01 to 0.999. The shift in absorption properties is explained by the phase change process of vanadium oxide (MIT). The electric field intensity on the absorber surface at different temperatures was monitored and analysed as a way to correlate the VO2 film phase transition process. The impedance matching theory is applied to explain the high level of absorption generated by the absorber. Finally, the effects of the structural parameters on the performance of the absorber are analysed. This work will have many applications in the terahertz field and offers a wide range of ideas for the design of terahertz-enabled devices.

Cheng Y., Yu J., Li X.

In this paper, we present an effective design of a tri-band high-efficiency circular polarization (CP) convertor based on double-split-ring resonator (DSRR) structures in the microwave region. The proposed CP convertor is composed of a periodic array of sub-wavelength tri-layered DSRR structures separated by a dielectric spacer, which can convert the normal incident CP wave to its orthogonal one at the three different resonance frequencies. Numerical simulation results indicate that the cross-polarization transmission coefficients of CP wave can achieve maximum values of 0.81 at 6.95 GHz, 0.65 at 10.55 GHz, and 0.81 at 12.85 GHz, respectively, which is in reasonable agreement with experiment. In addition, the corresponding CP conversion efficiency is over 90% at three different resonance frequencies. The simulated surface current distributions indicate that the high-efficient CP conversion properties are mainly attributed to the near field electric and magnetic dipole coupling between the adjacent DSRR layers. Due to its excellent tri-band CP properties, the proposed structure would find potential applications in the fields of remote sensing, radar, and satellite communication.

Wu X., Zheng Y., Luo Y., Zhang J., Yi Z., Wu X., Cheng S., Yang W., Yu Y., Wu P.

A four-band terahertz tunable narrow-band perfect absorber based on a bulk Dirac semi-metallic (BDS) metamaterial with a microstructure is designed. The three-layer structure of this absorber from top to bottom is the Dirac semi-metallic layer, the dielectric layer and the metal reflector layer. Based on the Finite Element Method (FEM), we use the simulation software CST STUDIO SUITE to simulate the absorption characteristics of the designed absorber. The simulation results show that the absorption rate of the absorber is over 93% at frequencies of 1.22, 1.822, 2.148 and 2.476 THz, and three of them have achieved a perfect absorption rate of more than 95%. We use the localized surface plasmon resonance (LSPR), impedance matching and other theories to analyze its physical mechanism in detail. The influence of the geometric structure parameters of the absorber and the incident angle of electromagnetic waves on the absorption performance has also been studied in detail. Due to the rotational symmetry of the structure, the designed absorber has excellent polarization insensitivity. In addition, the maximum adjustable range of absorption frequency is 0.051 THz, which can be achieved by changing the Fermi energy of BDS. We also define the refractive index sensitivity (S), which is 39.1, 75.4, 119.1 and 122.0 GHz RIU-1 for the four absorption modes when the refractive index varies in the range of 1 to 1.9. This high-performance absorber has a very good development prospect in the frontier fields of bio-chemical sensing and special environmental detection.

Xiong H., Ma X., Zhang H.

Heat-sensitive materials have great applications in sensor, detector, and tunable photoelectric devices. However, the wave-thermal effect of the heat-sensitive material is rarely been investigated in the THz range. Here, we propose the incorporation of heat-sensitive material (strontium titanate (STO)) within a THz absorber. The simulated results show that the absorptance and frequency can be dynamically controlled by the temperature of STO. Because the absorbed THz waves are finally converted into heat, then we research the theoretical mechanism of heat generation. Theoretical analysis shows that there are two reasons for the temperature rise: surface plasmon polariton (SPP) and ohmic loss of gold patch; Electromagnetic energy consumption inside the loss materials. To verify the theory, finally, we use COMSOL Multiphysics to research the nanosecond wave-thermal effect. The transient temperature of the wave-thermal effect is calculated quantitatively. The quantitative prediction of temperature variation can provide good guidance for thermal regulation and wave-thermally tunable THz devices.

Cheng Y., Li Z., Cheng Z.

In this paper, a terahertz perfect absorber (PA) made of all-dielectric metasurface with periodic sub-wavelength InSb micro-rod array in terahertz (THz) region was proposed, which can be functioned for temperature and refractive index (RI) sensing application simultaneously. Simulation results show that the absorbance of 99.9% at 1.757 THz and the Q-factor of about 53.24 under room temperature ( T = 295 K) can be obtained for this proposed PA. The perfect absorption is mainly contributed to the fundamental dipolar resonance inside the unit-cell structure. The resonance absorption properties of the PA can be adjusted by changing the geometric parameters of the structure. The proposed PA has a sensitivity of about 4.2 GHz/K since the electrical property of the InSb is highly dependent on the surrounding thermal radiation, which can be served as a temperature sensor. In addition, the PA also can be functioned as a RI sensor due to its higher Q-factor. As proofs of the RI sensing application, the sensitivity of the PA-based RI sensor about 1043.3 GHz/RIU at 295 K, and 920 GHz/RIU at 300 K can be obtained. Therefore, the narrow-band PA could be found promising applications on sensors, detectors, filters, and other optoelectronic devices in THz region. • Narrow-band tunable THz perfect absorber (PA) based on InSb metasurface was proposed. • The absorbance of PA is 99.9% at 1.757 THz and the Q-factor is about 53.24 when temperature 295 K. • Perfect absorption due to the fundamental dipolar resonance in the InSb metasurface. • The proposed PA can be served as both temperature and refractive index (RI) sensor.

Zhang M., Song Z.

Based on the phase-transition property of vanadium dioxide (VO2), a terahertz bifunctional absorber is proposed with switchable functionalities of broadband absorption and multiband absorption. When VO2 is metal, the system is regarded as a broadband absorber, which is composed of VO2 patch, topas spacer, and VO2 film with metallic disks inserted. The system obtains a broadband absorption with absorptance >90% from 3.25 THz to 7.08 THz. Moreover, the designed broadband absorber has a stable performance within the incident angle range of 50°. When VO2 is dielectric, multiband absorption with six peaks is realized in the designed system. Graphene and the metallic disk-shaped array play the dominant role in the mechanism of multiband absorption. Through changing the Fermi energy level of graphene, the performance of multiband absorption can be dynamically adjusted. Because of the switchable functionalities, the proposed design may have potential application in the fields of intelligent absorption and terahertz switch.

Cheng Y., Liu J., Chen F., Luo H., Li X.

We numerically demonstrate an optically switchable broadband metasurface absorber (MSA) structure based on planar patterned photoconductive silicon (Si) in terahertz (THz) region. The designed MSA is composed of planar-square-ring-shaped (PSRS) structure photoconductive Si array placed over a ground-plane separated by a dielectric substrate. The electric conductivity of the PSRS Si array can be controlled through the external optical pump beam. Through adjusting the electrical conductivity of the Si array, the structure can realize a switching absorption from 2.8% to 99.9%, and the relative bandwidth of the continuous absorption of 90% is tuned from 16.2% to 86.4%. Thus, the corresponding modulation depth of the proposed structure is up to 97.2%, and frequency tuning bandwidth of the continuous absorption of 90% is about 81.25%. The broadband stronger absorption of the structure mainly originates from the excitation of the fundamental dipolar mode. In addition, this design is polarization-independent and wide angles for both incident transverse electric (TE) and transverse magnetic (TM) waves. The Fabry-Perot interference theory is used to analyze the operation mechanism of the structure, and the theoretical results agrees well with simulations. Furthermore, the broadband absorption properties can be adjusted by varying the geometric parameters of the structure. Due to its excellent optically switchable response, the proposed structure may find potential applications in dynamic functional THz devices, such as modulators, switches, reflector and absorber.

Yue L., Wang Y., Cui Z., Zhang X., Zhu Y., Zhang X., Chen S., Wang X., Zhang K.

Perfect metasurface absorbers play a significant role in imaging, detecting, and manipulating terahertz radiation. We utilize all-dielectric gratings to demonstrate tunable multi-band absorption in the terahertz region. Simulation reveals quad-band and tri-band absorption from 0.2 to 2.5 THz for different grating depths. Coupled-mode theory can explain the absorption phenomenon. The absorption amplitude can be precisely controlled by changing the pump beam fluence. Furthermore, the resonant frequency is sensitive to the medium’s refractive index, suggesting the absorber may be of great potential in the sensor detection field. The experimental results exhibit a high detectivity of pesticides.

Liu W., Song Z.

A dual-tunable metamaterial absorption modulator is proposed based on a hybrid vanadium dioxide-graphene configuration. When vanadium dioxide is in the state of metal, the design serves as a narrowband absorber. It is composed of vanadium dioxide patch, topas spacer, and vanadium dioxide film. When vanadium dioxide is in the state of dielectric, the design serves as a broadband absorber. It includes vanadium dioxide patch, topas spacer, graphene layer, vanadium dioxide film, topas spacer, metal substrate. By adjusting Fermi level of graphene from 0.1 eV to 0.7 eV, absorptance of the proposed absorber can be dynamically tuned from 45.3% to 94.5% at 0.4 THz and from 31% to 96.3% at 1.0 THz, and absorption bandwidth gradually widens. Because of the unique dielectric to metal transition properties of vanadium dioxide, the tunable behavior of absorption frequency and intensity can be achieved through external stimuli. Thus our design can realize adjustable absorption of intensity and frequency in terahertz range. Besides, the designed narrowband and broadband absorbers are polarization-insensitive for small incident angle due to the symmetry, and absorptions of the design keep good performance within the angle range of 50 ° .

Zhang H., Cheng Y., Chen F.

A quad-band plasmonic perfect absorber (PPA) based on all-metal nanostructure metasurface in infrared regime has been proposed and investigated numerically, which could be applicable for refractive index (RI) sensing. The proposed PPA is made of all-metal nanostructure with an assembly array of vertical split-ring and multiple cylinders. The proposed PPA can achieve the absorbance of 99.34 %, 99.87 %, 99.85 %, and 99.85 % at 86.05 THz, 239.35 THz, 297.45 THz, and 344.35 THz, respectively. In addition, the quality-factor (Q-factor) of the PPA is about 9.6, 23.9, 40.7, and 74.1, respectively. The quad-band perfect absorptions are mainly originated from the hybrid modes between the surface plasmonic resonances (SPRs) and guided modes (GMs). Due to its higher Q-factor, it is believed that the proposed PPA could be served as a RI sensor. As a proof, a designed PPA based sensor has been demonstrated a high sensitivity of about 4367, 2162, 1059, and 908 nm/refractive index unit (RIU), respectively. Relying on its excellent performance, the proposed quad-band PPA could be found potential applications in the sensing, detecting and infrared spectroscopy.

Hossen M.S., Islam M.T., Kirawanich P., Hoque A., Alenezi A.M., Baharuddin M.H., Alsaif H., Soliman M.S.

Xu Y., Wang B., Zhou J.

Wang Q., Ju X., Yang C., Zhang Y., Hu J.

Abstract Dielectric nanomaterials have attracted significant attention in the realm of micro- nano optics owing to the simultaneous low ohmic loss and distinctive electromagnetic resonance characteristic. However, achieving both ultra-narrow multi-band band and perfect absorption effects simultaneously has been challenging due to the weak magnetic response within traditional dielectric metamaterials. In this work, employing the finite-time domain differential method for simulation calculations, a multi-band perfect absorber consisting of titanium dioxide cylinder arrays is theoretically proposed. Benefiting from the concurrent presence of electromagnetic lattice resonance within the arrays of titanium dioxide cylinders, the as-proposed optical absorber demonstrates the simultaneous achievement of triple absorption bands, with extremely narrow spectral characteristics (minimum bandwidth approximately 0.8 nm) and near-perfect absorption rates (around 95.6%, 96.8%, and 95%) in 700–900 nm. Further near-field analysis unveils that surface lattice resonance arises from the synergistic interaction between the incident light and periodic structures, enhancing the coupling efficiency between the light and the surface plasmon, which can significantly amplify the electromagnetic field. By adjusting the lattice constant and geometric parameters, the physical mechanisms of the structure are further elucidated, and the optimal parameters of the absorber are ultimately determined. Moreover, due to its exceptional optical properties, the as-proposed multi-band absorber can be employed as a high-efficiency refractive index sensor with multi-frequency channel sensing. The corresponding sensitivity is calculated to be 356, 443.6 and 305.9 nm/RIU, with corresponding figure of merits of 482, 460.4 and 19.5 RIU−1, respectively. This research establishes a robust foundation for advancing multi-band perfect optical absorber, offering significant potential applications in multiple fields such as biochemical sensing, surface enhancement spectroscopy, and nonlinear nano-optics.

Jia T., Li B., Gu B., Zhan Q., Rui G.

Banerjee S., Ghosh I., Santini C., Mangini F., Citroni R., Frezza F.

This research proposes an all-metal metamaterial-based absorber with a novel geometry capable of refractive index sensing in the terahertz (THz) range. The structure consists of four concentric diamond-shaped gold resonators on the top of a gold metal plate; the resonators increase in height by 2 µm moving from the outer to the inner resonators, making the design distinctive. This novel configuration has played a very significant role in achieving multiple ultra-narrow resonant absorption peaks that produce very high sensitivity when employed as a refractive index sensor. Numerical simulations demonstrate that it can achieve six significant ultra-narrow absorption peaks within the frequency range of 5 to 8 THz. The sensor has a maximum absorptivity of 99.98% at 6.97 THz. The proposed absorber also produces very high-quality factors at each resonance. The average sensitivity is 7.57/Refractive Index Unit (THz/RIU), which is significantly high when compared to the current state of the art. This high sensitivity is instrumental in detecting smaller traces of samples that have very correlated refractive indices, like several harmful gases. Hence, the proposed metamaterial-based sensor can be used as a potential gas detector at terahertz frequency. Furthermore, the structure proves to be polarization-insensitive and produces a stable absorption response when the angle of incidence is increased up to 60°. At terahertz wavelength, the proposed design can be used for any value of the aforementioned angles, targeting THz spectroscopy-based biomolecular fingerprint detection and energy harvesting applications.

Mehandiratta G., Kaler R.S.

Chen Y., Miao Y., Zhang W., Wei J., Fan R., Sun G., Wang Q.

Agrawal A., Kumar A., Panwar R.

Thomas S., Adithi Shenoy K., Satyanarayan M.N.

Yadav S.K., Maurya V., Singhal S.

Singhal S.

—This paper investigates a dual-side, dual-mode reflective cross-polarization converter for biosensing applications. The converter consists of a polyimide substrate with a modified dumbbell-shaped resonator on one surface and its complementary slot on another. The overall volume is 8.25μm × 8.25μm × 2.47 μm with dual-band operation of 6.39268–7.311692 THz and 9.783001–23.53473 THz for PCR≥80 % for front signal incidence and two full widths at half maximum (FWHM) bands i.e. 11.71594–12.26761 THz & 19.12042–19.87691 THz for back signal incidence. The periodicity is ∼λo/6, and substrate thickness is ∼λo/19 at 6.39268 THz. This device has performance stability for incident angle (θ)≤30o. The performance of this device can be tuned from dual-band operation to single-band by varying the chemical potential of the graphene strip for signal incidence from both sides. This device can classify cancer or tuberculosis-infected cells concerning healthy cells by using the variations in their corresponding refractive indices that lead to changes in the band edge frequencies. This device can differentiate between infected and healthy cells or different refractive indices with a high sensitivity of ∼5 THz/RIU. This device has merits of dual side sensing, wide operating bandwidth, multiple frequencies for sensing purposes, and high sensitivity over previously reported sensors.

Armghan A., Alsharari M., Baqir M.A., Saqlain M., Aliqab K.

Solar radiation is the Earth's most plentiful renewable energy source.

Feng S., Yang L., Cai B., Yang W., Wu L., Cheng Y., Chen F., Luo H., Li X.

Gupta R., Dwivedi R.P., Sbeah Z.A., Sorathiya V., Alwabli A., Alghamdi A., Faragallah O.S.

This paper presents a plasmonic metamaterial sensor utilizing gold resonator gratings with different radii for the cylindrical gratings. The sensor is simulated using the finite element method (FEM) in the infrared wavelength range of 0.7 to 2.5 µm. The sensor structure consists of six layers, with the gold resonator on the top, beneath it a Ge–Sb–Te (GST) substrate sandwiched between two silicon (Si) substrates and then a MXene substrate sandwiched between two SiO2 substrates. The design exhibits distinct reflectance characteristics across the proposed range, which is suitable for different sensing applications. A comparison is made between the two states of GST (amorphous and crystalline) to investigate the sensitivity of the device. Geometrical parameters, including the height of GST and Si, are optimized, changing the oblique incident of light, and three types of comparisons are conducted. Firstly, a sensitivity comparison is made between this work and previously published research. Secondly, a quality factor and figure of merit comparison is performed. Lastly, a sensitivity comparison is made between different sensing techniques and the technique employed in this work. After optimizing the design parameters, the device demonstrates the highest detection sensitivity, yielding results of sensitivity equal to 800 nm /RIU. The proposed design-based metamaterial can be utilized as a lab-on-chip sensor.

Zheng Y., Zhao W., Song Q., Ma C., Yi Z., Zeng Q., Sun T., Chen J., Yan J.

In this work, we explore the possibility that a hexagonal ring structure can be used as a solar absorber and a thermal emitter for multiple applications. By using FDTD (finite-difference time-domain) Solutions for numerical simulation, the light source is set to 280 nm–2500 nm, and the following properties of the structure are studied. Firstly, the structure achieves an average absorption efficiency of 92.57 % and 97.88 % at AM (Air Mass) 1.5, and the bandwidth is 283 nm–2006 nm (absorption efficiency greater than 90 %), which achieves ultra-broadband perfect absorption. Secondly, the structure can theoretically work at 1500 K, at which the thermal radiation efficiency is 89.13 %. When considering the oxidation and decomposition of materials in practical applications, the structure can work up to 700 K, and the thermal radiation efficiency decreases to 77.07 %. Therefore, the structure has excellent absorption and radiation performance, and has a wide range of applications as a solar absorber or thermal emitter.