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Graphene has great potential in wearable sensors. However, the sensing selectivity of graphene‐based sensors is still a big challenge, limiting their application in the multifunctional sensors. Herein, different types and distributions of defects are introduced into graphene by femtosecond laser patterning to realize sensing selectivity for wearable multifunctional sensors. The imperfect graphene with four pattern arrays, circle, square, triangle, and hexagon with none, right, acute, and obtuse angle, is fabricated by laser to control the types and distributions of defects. The graphene with different patterns shows remarkable sensing selectivity, owing to the dangling bonds and vacancies on the edge of patterns. The graphene‐based sensor with the circle pattern array is used to detect the strain variation; the triangle one is for temperature detection; and the hexagon one can collect the information of gas. The gauge factor is demonstrated to be as high as ≈104. The as‐produced sensor with the above‐mentioned four patterns can simultaneously detect body pulse, temperature, and harmful gas by attaching to human body or clothes, offering real‐time health monitoring and protection. The patterned graphene‐based sensors with high sensing selectivity are expected to develop multifunctional sensor platform and versatile artificial electronic skin. [ABSTRACT FROM AUTHOR]

Abstract In the study, an improved superconducting heterojunction is made up of a zigzag graphene nanoribbon, which is patterned by a triangle and supports localized edge mode. Since all the localized edge modes stem from a pattern operation, the structure features of the pattern exert an enormous function on the coherent quantum transport. Especially, the patterned modes can enhance the Andreev reflection largely both in the ferromagnetic nanoribbon edge and the antiferromagnetic nanoribbon edge. The spin resolved zero bias conductances, in sharp contrast to its counterpart in the infinite width superconducting heterojunction, exhibit the different dependence on the patterned ferromagnetic interaction. Highlights • We propose a zigzag graphene nanoribbon graphene nanoribbon/superconductor heterojunction which is patterned by the triangle and supports localized edge mode. • The energy band and density of the states in the central scattering region have a closed relationship with the localized edge mode. • Patterned modes can enhance the Andreev reflection largely in the subgap both in the ferromagnetic nanoribbon edge and antiferromagnetic nanoribbon edge. • Spin-resolved zero-bias conductances exhibit the different dependence on the patterned ferromagnetic interaction. [ABSTRACT FROM AUTHOR]

In this study, we establish the universal characteristics of the contributions of the Rashba spin orbit interaction (RSOI) and the Dresselhaus spin orbit interaction (DSOI) to the supercurrent in a graphene Josephson junction. The most striking property of the skewness and the critical supercurrent, so far not unequivocally revealed, is the presence of a maximum value or a single singularity at the key point (the DSOI equates to half of the RSOI) in pristine case. This is in sharp contrast to that in conventional Josephson junction (the π junction) and its counterpart in heavily doped graphene case (monotonically decay). Using a general delta potential model, we determine the barrier effect on the quasilocalized Andreev level ( π periodic) and the propagating Andreev mode ( π/ 2 periodic). Moreover, we trace the pronounced critical supercurrent Fabry–Pérot oscillations patterns as a function of the doping level, and find that it shows a good qualitative agreement with the recent experiment of M. Ben Shalom et al. [Nat. Phys. 12, 318 (2016)]. Our results show that definitive signatures of specular Andreev reflection can be observed in the graphene material and suggest that the graphene Josephson junction can lead to a new possible application in quantum computing. [ABSTRACT FROM AUTHOR]

Based on the Dirac–Bogoliubov–de Gennes equation, the chirality-resolved transport properties through a ballistic graphene-based superconducting heterojunction with both the Rashba and the Dresselhaus spin orbit interaction have been investigated. Our results show that, in contrast to the retro-Andreev reflection suppressed by the spin orbit interaction (SOI), the specular Andreev reflection (SAR) can be enhanced largely by the SOI. Moreover, the Fabry–Perot interferences in the barrier region lead to the oscillating feature of the tunneling conductance. It is anticipated to apply the qualitative different results to diagnose the SAR in single layer graphene in the presence of both kinds of the SOI. [ABSTRACT FROM AUTHOR]

Transport characteristics of relativistic electrons through graphene-based d-wave superconducting double barrier junction and ferromagnet/ d-wave superconductor/normal metal double junction have been investigated based on the Dirac-Bogoliubov-de Gennes equation. We have first presented the results of superconducting double barrier junction. In the subgap regime, both the crossed Andreev and nonlocal tunneling conductance all oscillate with the bias voltage due to the formation of Andreev bound states in the normal metal region. Moreover, the critical voltage beyond which the crossed Andreev conductance becomes to zero decreases with increasing value of superconducting pair potential α. In the presence of the ferromagnetism, the MR through graphene-based ferromagnet/ d-wave superconductor/normal metal double junction has been investigated. It is shown that the MR increases from exchange splitting h=0 to h= E (Fermi energy), and then it goes down. At h= E, MR reaches its maximum 100. In contrast to the case of a single superconducting barrier, Andreev bound states also manifest itself in the zero bias MR, which result in a series of peaks except the maximum one at h= E. Besides, the resonance peak of the MR can appear at certain bias voltage and structure parameter. Those phenomena mean that the coherent transmission can be tuned by superconducting pair potential, structure parameter, and external bias voltage, which benefits the spin-polarized electron device based on the graphene materials. [ABSTRACT FROM AUTHOR]

Based on the transfer-matrix method, the transport properties of electrons in the multilayers structure with the spatially-modulated strength of spin-orbit interactions (SOIs) have been investigated. We show that the transmission and the conductance oscillate with the parameters of the structure and the incident energy. In particular, when only the Rashba spin-orbit interaction (RSOI) exists, in sharp contrast to its counterpart in conventional junctions, the minima of the normal transmission probabilities just reach a constant value 0.5. [ABSTRACT FROM AUTHOR]

We show that the angle resolved transmission probability through the graphene-based double junctions with the spin-orbit interactions (SOIs) can be efficiently controlled by the SOIs strength, the parameter of the junctions, and the incident energy of the electron. It is anticipated to apply such a phenomenon to design an electron wavevector filter based on the graphene material by a pure electrical method. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, an analytical form of the real-space non-interacting Green function of graphene material is developed. The transport properties of the relativistic electron through graphene-based double barrier structures have been investigated based on the real-space non-interacting Green function. It is shown that the results computed by the real-space non-interacting Green function are in perfect agreement with those results, which is based on the transfer matrix method. [Copyright &y& Elsevier]

Abstract: Based on the transfer-matrix method, we have investigated the coherent quantum transport in a graphene-based normal metal–insulator–superconductor () junctions, in the limit of a thin barrier. It is found that the conductance spectra of such system, in contrast to a π periodic oscillatory behavior is shown for aligned Fermi surfaces of the normal and superconducting regions, exhibit a new periodic oscillatory behavior as a function of barrier strength (χ) for a large Fermi surface mismatch. [Copyright &y& Elsevier]

• SiC is modified by graphene foam and carbon nanotube for electromagnetic shielding. • Interconnected conductive graphene network sharply increases the electric loss. • Rich structural defects and multiscale interfaces generate extra polarization loss. • Modified SiC shows lightweight and excellent electromagnetic shielding performance. Carbon nanotube/graphene foam/silicon carbide (CNT/GF/SiC) composites are prepared by in-situ growth of CNT in GF and followed by infiltration and pyrolysis of CNT-dispersed polycarbosilane. Results show that the CNT/GF/SiC composites exhibit outstanding electromagnetic interface (EMI) shielding effectiveness (SE) of 32.1 dB in X-band, especially the specific SE reaches up to 33.8 dB cm3/g with a low density of 0.95 g/cm3. The interconnected conductive graphene network improves the conductivity and sharply increases electric loss; meanwhile, the rich structural defects and multiscale interfaces including GF-CNT interface and CNT-SiC interface offer additional polarization loss, both of which endow composites with outstanding EMI shielding performance. [ABSTRACT FROM AUTHOR]

Abstract: Crossed Andreev reflection (CAR) under the influence of anisotropic pairing symmetry is considered. It is shown that CAR is sensitive to the Fermi energy and the orientation of the gap. In addition, the oscillatory period of CAR can be not only tunable by the potential energy in the superconductor region, it also can be modulated by the length of the superconductor region. The physical origination for those phenomena has also been analyzed. [ABSTRACT FROM AUTHOR]

Abstract: We have investigated the transport properties in the graphene-based normal metal/insulator/-wave superconductor junctions, in the limit of a thin barrier. It is shown that the conductance spectra and the shot noise of such system exhibit essential different features as compared to the conventional spin-triple and the graphene-based spin-singlet superconductor junctions. [Copyright &y& Elsevier]

Abstract: Based on the transfer-matrix method, we have investigated the coherent quantum transport in a graphene-based normal metal–insulator–superconductor–insulator–normal metal (NG/IG/SG/IG/NG) double junctions with a barrier of thickness d and with a potential strength V 0 applied across the barrier region. It is found that all the reflection coefficients in BTK theory as well as conductance spectra of such system oscillate with the external voltage and the barrier strength V 0. The oscillation feature of conductance can be tuned largely by the thickness of the superconductor interlayer. These phenomena are essentially different from those found in conventional normal metal–superconductor double junctions. The physical origin for those phenomena has also been analyzed. [Copyright &y& Elsevier]

In this study, based on the Dirac–Bogoliubov–de Gennes equation, we theoretically investigate the interaction effect between the anisotropic d-wave pairing symmetry and the spin orbit interaction (the Rashba spin orbit interaction (RSOI) and the Dresselhaus spin orbit interaction (DSOI)) in a graphene superconducting heterojunction. We find that the spin orbit interaction (SOI) plays a critical role on the tunneling conductance in the pristine case, but minimally affecting the tunneling conductance in the heavily doped case. As for the zero bias state, in contrast to the keep intact feature in the heavily doped case, it exhibits a distinct dependence on the RSOI and the DSOI in the pristine case. In particular, the damage of the zero bias state with a slight DSOI results in the disappearance of the zero bias conductance peak. Moreover, the tunneling conductances also show a qualitative difference with respect to the RSOI when both the RSOI and the DSOI are finite. These remarkable results suggest that the SOI and the anisotropic superconducting gap can be regarded as a key tool for diagnosing the specular Andreev reflection. [ABSTRACT FROM AUTHOR]

[Display omitted] • Single-atom Cu was successfully doped into graphene via N doping. • The interaction between single-atom Cu and N -graphene inhibited Cu leaching. • O 2 •− and active chlorine were the main active substances triggered by 1Cu@NG for acetaminophen electrocatalytic degradation. • The degradation efficiency of 1Cu@NG reached 100 % within 90 min at a current of 15 mA. Acetaminophen (APAP), as a pharmaceutical contaminant, can be degrade by electrocatalysis. However, the anode material is the main factor for electrocatalysis. Taking synergistic advantages of metal and graphene catalysts as anode is an effective way to improve the efficiency of electrocatalysis. Combining single metal atoms with graphene to maximize atom utilization efficiency of metal active center remains a challenge. This research fabricates single-atom copper (Cu) and nitrogen (N) atom-codoped graphene (1Cu@NG) as electrocatalytic anode. A series of characterizations disclose that the incorporation of N could be used as an anchor site for single-atom Cu, and the activity and stability of 1Cu@NG are optimized by interfacial interaction between single-atom Cu and N -doped graphene (NG). In 10 mg/L APAP with 1 g/L NaCl, the degradation efficiency of 1Cu@NG is 100 % within 90 min at current of 15 mA and leaching amounts of Cu ion is < 0.05 mg/L. The degradation efficiency of 1Cu@NG after four cycles is 97.13 % in 90 min and still maintain low ion leaching amounts (<0.05 mg/L). The main active substances produced by 1Cu@NG in the electrocatalytic degradation process are O 2 •− and active chlorine. In addition, the possible degradation pathways of APAP are explored. [ABSTRACT FROM AUTHOR]

Graphene shows excellent performance as the thinnest protective coating, such as super-high electrical conductivity, thermal conductivity, anticorrosion, and antifriction. However, graphene cannot provide sustainable protection as the surface coating due to its nanoscale thickness. Here, we explored a novel approach to repairing the damaged area of graphene film by laser induced regrowth of graphene. Graphene film was firstly in-situ grown on the nickel surface, along with a large number of carbon sources implanted into the nickel bulk. Once the surface graphene was damaged, the carbon source in the bulk would be re-precipitated by the laser inducing to form new graphene film on surface and repair the damaged area. The regrowth process depended strongly on the way of thermal input and the laser parameters. The results showed that only under the appropriate laser parameters, the graphene can be successfully regrown on the damaged area. The mechanism of regrowth and self-repairing was discussed by experiment results and theoretic analysis. This in-situ self-repaired graphene/carbon-rich metal composite shows a great potential in the field of metal protection against corrosion, friction, arc-ablating, etc. [Display omitted] • After damaging, graphene can be regrown to repair the damaged area locally by laser induction. • Secondary growth of graphene was motivated by thermal input and structure stability. • The carbon atoms migrated from substrate body to surface through Schottky defects. • By varying the parameters of laser process, the high-quality new piece of graphene can be obtained. [ABSTRACT FROM AUTHOR]

Based on the first-principles calculations, we studied the structure and electronic properties of HfSSe/Graphene (HfSSe/Gr) and Graphene/HfSSe (Gr/HfSSe) van der Waals heterostructures (vdWHs) under the effects of external electric field and interlayer distance. The results show that the electronic properties of HfSSe/Gr and Gr/HfSSe heterostructures are not sensitive to interlayer distance, and the heterostructures always maintain n-type Schottky contact when the interlayer distance changes. Under the different applied electric field, the Schottky barrier of heterostructures can be regulated from n-type Schottky contact to p-type Schottky contact, and it can be further adjusted to Ohmic contact. In summary, these results are useful in nanoelectronic and optoelectronic devices in the future experiments. [Display omitted] • HfSSe/Gr and Gr/HfSSe heterostructures are n-type Schottky contact. • Heterostructures maintains n-type Schottky contact as the interlayer distance changes. • Potential drop of 9.71eV and 9.84eV exist in the HfSSe/Gr and Gr/HfSSe heterostructures. • The SBH and contact types of the heterostructures can be regulated by applying external electric field. [ABSTRACT FROM AUTHOR]

[Display omitted] • Selective sensitivity of CO/NO/H 2 O-mixed gas was derived from topologic graphene. • The given topology can precisely detect one specific gas from mixed gases. • The topologic graphene had superb sensing performance with high GF of ~104. • DFT was carried out to further understand the mechanism of selective sensing. Graphene with antidots shows great potential in wearable devices and highly sensitive sensors. In this paper, we fabricated the patterned graphenes of circle, square, and triangle by ultrafast laser processing. The given patterned graphene can precisely detect one specific gas from the CO/NO/H 2 O-mixed gases. The sensing performance results demonstrated that the circle patterned graphene (cir-graphene) was most sensitive to CO with the highest sensitivity with the gauge factor (GF) of 3.9 × 104. For NO sensing, the triangle patterned graphene (tri-graphene) conducted the best results. The square patterned graphene (squ-graphene) was the most sensitive to H 2 O. The DFT calculations revealed that CO was chemical adsorbed on cir-graphene with the most negative adsorption energy (−3.638 eV). For NO sensing, tri-graphene performed best. While, the patterned graphene was not available to H 2 O sensing. This work offers a novel solution to next-generation wearable multifunctional sensors, and a new insight for the selective sensing mechanism. [ABSTRACT FROM AUTHOR]

Abstract: The transmission character in the present superlattice under the influence of disorder is considered. It is shown that transmission coefficients are sensitive to the disorder strength and the system size. In particular, the Klein tunneling can be suppressed by disorder to a neglectable value only when the ISOI exists. In addition, the transmission channel through the system in the normal incidence case can be tuned by the system size only when the RSOI exists. The physical origination of those phenomena has also been analyzed. [Copyright &y& Elsevier]

Abstract: Based on the transfer-matrix method, the spin-polarized transport properties of electrons through ballistic graphene-based quantum tunneling junctions with spatially modulated strength of spin–orbit interactions (SOIs) have been investigated. It is shown that magnetoresistance (MR) oscillates with the SOI strength, number of the layers, and incident energy. Application of such a phenomenon to design spin-polarized electron devices based on the graphene material is anticipated. [Copyright &y& Elsevier]

Abstract: Based on the transfer-matrix method, we show that the angle resolved transmission probability through the graphene-based structure with the spatially modulated strength of spin–orbit interactions (SOIs) can be efficiently controlled by SOIs strength, number of layers, and incident energy of the electron. It is anticipated to apply such a phenomenon to design an electron wavevetor filter based on the graphene material by a pure electrical method. [ABSTRACT FROM AUTHOR]

Abstract: Based on the transfer-matrix method, we have investigated the spin polarized transport properties of the electrons through ballistic graphene-based quantum tunneling junction with the Rashba spin–orbit interaction (RSOI). It is found that the spin-dependent conductance as well as the spin polarization rate oscillates with the RSOI strength λ R and the energy E of the incident electron. The oscillation features of the spin polarization rate and the conductance can be tuned largely by the RSOI for λ R ⪡E, while for λ R ≥E they are almost independent of the RSOI. These phenomena are essentially different from those found in conventional double tunneling junction. [ABSTRACT FROM AUTHOR]