Black Phosphorus Graphene Research Articles

Tunable plasmon-induced transparency in anisotropic graphene-black phosphorus photonic device for high-performance sensors and switchers

A novel photonic device composed of graphene and black phosphorus (G-BP) has been proposed, which achieves high-performance plasmon-induced transparency (PIT) effect within the THz range and maintains substantial tunability and anisotropy. The anisotropy of the PIT effect arises from the near-field coupling between two bright modes characterized by distinct effective electron masses of BP, resulting transparency window at 33.35 THz for TE polarization and at 26.92 THz for TM polarization. Through the modulation of Fermi energy in graphene, doping levels of BP and geometric parameters separately, a tunable transparency window is achieved. Notably, the convergence or divergence of the anisotropic transparency windows can be well manipulated with different BP doping levels. Furthermore, the proposed G-BP photonic device exhibits a high sensitivity to changes in the surrounding refractive index and substrates, with a maximum sensitivity of 12.04 THz/RI, rendering it suitable for sensor applications. Overall, the proposed photonic device exhibits notable PIT effects characterized by high anisotropic performance, substantial tunability, great sensitivity, and stability, making it a promising candidate for applications in sensors, polarizers, and switchers.

Tunable optical devices with multiple plasmon-induced transparency based on graphene-black phosphorus hybrid metasurface

In this research, we propose a simple and novel graphene-black phosphorus composite structure. Through the coupling mechanism of bright–bright mode, four layers of graphene and one layer of black phosphorus produce a quadruple plasmon-induced transparency (PIT) effect. The response of the proposed structure to the angle of polarized light is investigated, and it is found that the sensitivities of graphene and black phosphorus to the polarization angle of light are different. In addition, the dynamic regulation of PIT by the Fermi level of graphene and the carrier concentration of black phosphorus are discussed. The modulation depths of the fivefold optical switching are 96%, 99%, 87%, 93%, and 80%, respectively. The quadruple PIT can also be converted into triple PIT, in which single, dual, or triple optical switching are realized, respectively. Finally, with the change in the refractive index of the environment medium, the sensitivity response of the proposed structure is as high as 4.790 THz⋅RIU−1. We believe that this research will contribute to the development of optical switches, modulators, and sensors.

Theoretical analysis of epsilon-near-zero/surface plasmon polariton modes based on the graphene-black phosphorus heterostructure

We theoretically investigate the epsilon-near-zero (ENZ)/surface plasmon polaritons (SPPs) modes based on graphene-black phosphorus heterostructure. In the proposed hybrid graphene-black phosphorus structure, ENZ mode of black phosphorus and GSP can be simultaneously stimulated and take into effect. The enhanced optical field confinement induced by ENZ mode of black phosphorus and extended propagation distance induced by the surface plasmon polariton mode of graphene can be both obtained within the proposed graphene-black phosphorus heterostructure. The simulation results show that the figure of merit of the hybridized structure outperforms that of graphene or black phosphorus-based structures. It also reveals that the doping density of black phosphorus and the chemical potential of graphene would both contribute to the results of optical field confinement and propagation distance, and may lead to the tunable optimized working wavelength in the mid-infrared range (MIR). Our work may extend to design the opto-electro devices based on the hybridized 2D materials in the future nanophotonics.

Anisotropic perfect absorber based on black phosphorus-graphene

Two-dimensional materials have garnered extensive attention in the realm of optical devices due to their unique physical properties. In this paper, we propose a tunable and anisotropic perfect absorber composed of anisotropic black phosphorus (BP) and isotropic graphene. The plasmon resonance of this anisotropic material and isotropic material achieves a strong anisotropic plasma response. The proposed structure demonstrates absorption of 99.73 % and 98.35 % in the x- and y-polarization directions, respectively. By adjusting the geometric parameters and the levels of doping with graphene and BP, the resonance characteristics can be effectively controlled. In addition, the robustness to incident angle and polarization sensitivity is also illustrated. Consequently, our research offers broad prospects for applications in polarization-selective and tunable high-performance devices, such as polarizers, modulators, and mid-infrared spectral imaging.

Tunable plasmonic hybrid photonic device based on squared graphene and black phosphorus metamaterials

The yearning to utilize and control the captivating property of two-dimensional carbon materials has attracted plenty of attention in biosensing and optoelectronics. In this paper, we proposed a novel graphene-black phosphorus (BP) hybrid photonic device to exhibit strong absorption of 97.0 % at 12.23 μm in the x-direction and it is 93.3 % at 13.42 μm in the y-direction. Due to the surface plasmon resonance of graphene and distinctive anisotropic effective electron masses of black phosphorus along the armchair and zigzag axes, the electromagnetic coupling achieves an enhanced performance than individual graphene or BP layer. Additionally, by adjusting the Fermi energy of graphene, the doping level of BP, and the geometric parameters, the resonant absorption peaks can be tuned independently in both TE and TM polarization. The advantages of our proposed plasmonic hybrid photonic device include high anisotropic resonance, flexible tunability, great stability, and a simple design. These make it promising for applications in photodetectors, polarizers, and imaging systems.

Graphene-black phosphorus printed photodetectors

Layered materials (LMs) produced by liquid phase exfoliation (LPE) can be used as building blocks for optoelectronic applications. However, when compared with mechanically exfoliated flakes, or films prepared by chemical vapor deposition (CVD), LPE-based printed optoelectronic devices are limited by mobility, defects and trap states. Here, we present a scalable fabrication technique combining CVD with LPE LMs to overcome such limitations. We use black phosphorus inks, inkjet-printed on graphene on Si/SiO2, patterned by inkjet printing based lithography, and source and drain electrodes printed with an Ag ink, to prepare photodetectors (PDs). These have an external responsivity (R ext)∼337 A W−1 at 488 nm, and operate from visible (∼488 nm) to short-wave infrared (∼2.7 µm, R 48 mA W−1). We also use this approach to fabricate flexible PDs on polyester fabric, one of the most common used in textiles, achieving R 6 mA W−1 at 488 nm for an operating voltage of 1 V. Thus, our combination of scalable CVD and LPE techniques via inkjet printing is promising for wearable and flexible applications.

Near-unity broadband infrared absorption in a graphene-black phosphorus bimodal triple-layer structure

It is well known that both graphene and monolayer black phosphorus (BP) can excite and generate surface plasmonic resonances in the infrared spectrum, providing suitable conditions for strong light-matter interactions. To take full advantage of this benefit, a three-layered infrared absorbing structure with broadband absorption effect based on a hybrid graphene-BP metamaterial was developed. Using numerical research methods, the absorption effect of the structure could be well modulated by adjusting the geometrical parameters of the structure and the doping levels of graphene and BP. In addition, the sensitivity of the structure to the angle of incidence is also investigated. By optimizing the previous parameters, the structure achieves an absorption of more than 87.5% in the wavelength range from 10.1 to 24.5 um and a maximum absorption of 99.97%. The proposed broadband infrared structure could have many potential applications in infrared sensing, bio-imaging and environmental monitoring.

Design and Synthesis of Palladium/Black Phosphorus–Graphene Hybrids as High-Performance Catalysts for Ethanol Electrooxidation in Alkaline Media

In this study, a series of Pd-supported black phosphorus–graphene (Pd/BP-G) catalysts are prepared to explore their electrocatalytic performances in the electrooxidation of ethanol in alkaline media. The characterization results show that BP is combined with activated graphene to form a P–C bond and a P–O–C bond heterojunction. Pd nanoparticles equally anchor on the BP-G hybrid, and Pd/BP-G exhibited enhanced electrocatalytic activity for the ethanol oxidation reaction in alkaline media. The electrochemically active surface area and mass activity for the Pd/BP-G catalyst reached 210.4 m2·gPd–1 and 3960.0 mA·mgPd–1, which are 9.54 and 5.86 times higher than those of commercial Pd/C, respectively. Further studies show that Pd/BP-G catalysts have reliable stabilities and faster reaction kinetics. These results indicate that the prepared Pd/BP-G catalysts have great application potentials in direct ethanol fuel cells.

Interfacial effects on lithium-ion diffusion in two-dimensional lateral black phosphorus-graphene heterostructures.

Lateral heterostructures constructed from different two-dimensional (2D) materials can be potentially used in lithium-ion batteries (LIBs). The interface between two different components strongly affects LIB charge and discharge processes. Herein, the atomic structures, electronic properties, and Li-ion diffusion characteristics of lateral black phosphorus-graphene (BP-G) heterostructures are studied via first-principles calculations. The obtained results reveal that BP-G heterostructures with either zigzag (ZZ) or misoriented interfaces constructed according to Clar's rule possess a small number of interfacial states and are electronically stable. Furthermore, compared with the perfect ZZ interface of BP-G, Clar's interfaces provide a larger number of diffusion paths with much lower energy barriers. The findings of this study suggest that lateral BP-G heterostructures can provide insights for rapid charge and discharge processes in LIBs.

Tunable and anisotropic perfect absorber using graphene-black phosphorus nanoblock.

Two-dimensional (2D) materials, which have attracted attention due to intriguing optical properties, form a promising building block in optical and photonic devices. This paper numerically investigates a tunable and anisotropic perfect absorber in a graphene-black phosphorus (BP) nanoblock array structure. The suggested structure exhibits polarization-dependent anisotropic absorption in the mid-infrared, with maximum absorption of 99.73% for x-polarization and 53.47% for y-polarization, as determined by finite-difference time-domain FDTD analysis. Moreover, geometrical parameters and graphene and BP doping amounts are possibly employed to tailor the absorption spectra of the structures. Hence, our results have the potential in the design of polarization-selective and tunable high-performance devices in the mid-infrared, such as polarizers, modulators, and photodetectors.

Robust and Low-Power-Consumption Black Phosphorus-Graphene Artificial Synaptic Devices.

Two-dimensional (2D) black phosphorus (BP) materials, as the most promising building blocks for the development of artificial synapses, have attracted more and more attention. However, the instability of exfoliated 2D BP structures still remains a problem in the development of artificial synapse devices. In this study, the robust and low-power-consumption artificial-synaptic-based BP was successfully manufactured. The synapse devices have high stability in the air atmosphere and do not show obvious degradation over 3 months. The obtained devices not only implement the main function of synapses but also perform the function of dendritic neural synapses and simple logical operations, revealing their very strong learning behavior. The high mobility of 2D BP as well as the coupled effect and quantum confinement effect of the graphene oxide quantum dot (GOQD) can greatly boost the performance of BP-based synapse devices, such as low power consumption (62 pW) and high sensitivity (ultrasmall stimuli at an amplitude of -20 mV). Moreover, benefiting from the GOQD and the interaction between BP and graphene, the main dominated mechanism of the BP-graphene synapse device can be the capture and release of electrons by the 2D BP and GOQD instead of the conductive filament.

Graphene Plasmon-Enhanced Polarization-Dependent Interfacial Charge Transfer Excitons in 2D Graphene-Black Phosphorus Heterostructures in NIR and MIR Regions

Graphene Plasmon-Enhanced Polarization-Dependent Interfacial Charge Transfer Excitons in 2D Graphene-Black Phosphorus Heterostructures in NIR and MIR Regions

Dynamical manipulation of a dual-polarization plasmon-induced transparency employing an anisotropic graphene-black phosphorus heterostructure.

Dynamical tunable plasmon-induced transparency (PIT) possesses the unique characteristics of controlling light propagation states, which promises numerous potential applications in efficient optical signal processing chips and nonlinear optical devices. However, previously reported configurations are sensitive to polarization and can merely operate under specific single polarization. In this work we propose an anisotropic PIT metamaterial device based on a graphene-black phosphorus (G-BP) heterostructure to realize a dual-polarization tunable PIT effect. The destructive interference coupling between the bright mode and dark modes under the orthogonal polarization state pronounced anisotropic PIT phenomenon. The coupling strength of the PIT system can be modulated by dynamically manipulating the Fermi energy of the graphene via the external electric field voltage. Moreover, the three-level plasmonic system and the coupled oscillator model are employed to explain the underlying mechanism of the PIT effect, and the analytical results show good consistency with the numerical calculations. Compared to the single-polarization PIT devices, the proposed device offers additional degrees of freedom in realizing universal tunable functionalities, which could significantly promote the development of next-generation integrated optical processing chips, optical modulation and slow light devices.

Tuning photoresponse of graphene-black phosphorus heterostructure by electrostatic gating and photo-induced doping

Metal-semiconductor diodes constructed from two-dimensional (2D) van der Waals heterostructures show excellent gate electrostatics and a large built-in electric field at the tunnel junction, which can be exploited to make highly sensitive photodetector. Here we demonstrate a metal-semiconductor photodiode constructed by the monolayer graphene (Gr) on a few-layer black phosphorus (BP). Due to the presence of a built-in potential barrier (~0.09 ± 0.03 eV) at the Gr-BP interface, the photoresponsivity of the Gr-BP device is enhanced by a factor of 672%, and the external quantum efficiency (EQE) increases to 648% from 84% of the bare BP. Electrostatic gating allows the BP channel to be switched between p-type and n-type conduction. We further demonstrate that excitation laser power can be used to control the current polarity of the Gr-BP device due to photon-induced doping. The versatility of the Gr-BP junctions in terms of electrostatic bias-induced or light-induced switching of current polarity is potentially useful for making dynamically reconfigurable digital circuits.

Off/on switchable smart electromagnetic interference shielding aerogel

Summary Smart electromagnetic interference (EMI) shielding materials with tunable EM wave response characteristics are attractive for future EM devices. Here, we report an off/on switchable EMI shielding material that can be tuned from EM wave transmission to shielding and vice versa by mechanical compression and decompression. This smart material is prepared by filling conductive carbon nanoparticles into wood-derived lamellar carbon aerogel, showing reversible compressibility and strain-sensitive conductivity. The original aerogel has good impedance matching and low dielectric loss, allowing the EM wave to pass through. Mechanical compression enables the carbon nanoparticles to establish highly conductive pathways in the aerogel, which significantly increases the conductivity of aerogel and thus activates its EMI shielding performance. This function switch is reversible by repeatedly compressing and decompressing the aerogel. The availability of such a never-before-realized off/on switchable EMI shielding material provides an opportunity for the development of advanced smart EM devices.

Active control of plasmon-induced transparency with large tunability and high Q-factor in graphene-black phosphorus hybrid system

Plasmon-induced transparency phenomena in the mid-infrared caused by the coupling behavior between dipole (bright element) and higher-order modes (dark element) in graphene as well as black phosphorus (BP) nanoribbons are investigated. The transparent windows can be adjusted flexibly by varying the carrier concentration of graphene and BP. It is also shown that the carrier mobility and refractive index of the substrate are the key factors affecting destructive interference. Obvious group delays are obtained near the transparent windows so that the slow light effect can be achieved. Our results allow a better understanding of efficient exploration of surface plasmons with integrated properties of building blocks from a family of two-dimensional materials, with the aim of expanding both photonic bands and functionalities.

Theoretical study of SPP properties based on black phosphorus–graphene van der Waals heterostructure

We theoretically investigate the surface plasmon polariton (SPP) properties based on black phosphorus–graphene van der Waals heterostructures that can be tuned by both the incident light angle of black phosphorus and Fermi level of graphene. We elucidate the angle-dependent SPP properties for the hybrid structure from the visible regime to mid-infrared regime. The results show that the largest SPP propagation distance is obtained in the zigzag direction of black phosphorus except when the wavelength is tuned from 380 nm to 480 nm in the visible regime and 1 µm–1.2 µm in the near infrared regime. We also reveal the quasi-linear and quasi-square linear relationship between the SPP propagation distance and Fermi level of graphene for different regimes. Our work would be of great value to construct and optimize the angle-dependent and tunable SPP devices based on the hybridization of different 2D materials.

New RTDs with enhanced operation based on black phosphorus–graphene heterostructures and a semianalytical vdW tunneling model

Two new vertical resonant tunneling devices (RTDs) of different sizes are proposed herein to achieve negative differential resistance with enhanced tunneling and peak-to-valley ratio (PVR) stability. The proposed structures are of the form n+–p−–p+ (S2) and n+–[p−–n+]–p−–p+ (S1) with different electrodes made of parallel graphene nanoribbon and graphene sheet (S2) or bilayer graphene (S1). The results of the simulations show a PVR of 3–3.5 depending on the geometry of the structure, with a maximum current of 10 μA. Also, robust PVR values in the range of 1.2–1.5 are obtained for these structures for a wide range of dimensions. An approximate analytical model for the I–V curve under the assumption of a vertical van der Waals bonding stacked structure as equivalent to the complex horizontal channel is introduced.

Tunable attenuator based on hybrid graphene-black phosphorus microstrip line for terahertz applications

This paper presents a novel type of tunable attenuator based on hybrid graphene-black phosphorus microstrip line for terahertz applications. Two configurations are studied, the first is composed of a metal microstrip line and one or two graphene sheets, and in the second a BP sheet is placed under the graphene. A transverse equivalent network is proposed to offer the general understanding of the attenuation mechanism. The simulated result shows a strong agreement between the WCIP method and CST simulator, which confirms the accuracy of the algorithm developed by the WCIP method for the graphene, BP and hybrid area. The results suggest that the attenuator with two graphene sheets gives a wider tunable attenuation range when compared with the attenuator with one graphene sheet at only one side. Furthermore, by putting the graphene on the BP, the attenuation tuning range has been enhanced, where it increases from 2.10–23.96 dB to 3.85–31.69 dB.

Black Phosphorus: Black Phosphorus–Graphene Oxide Hybrid Nanomaterials toward Advanced Lubricating Properties under Water (Adv. Mater. Interfaces 23/2019)

Black Phosphorus: Black Phosphorus–Graphene Oxide Hybrid Nanomaterials toward Advanced Lubricating Properties under Water (Adv. Mater. Interfaces 23/2019)