Zigzag Boron Nitride Nanoribbons Research Articles

Transport properties of Mn-doped/adsorbed zigzag boron nitride nanoribbon based nanodevices

We are conducting research into the spin transport characteristics of models that are built from zigzag Boron Nitride Nanoribbons (ZBNNRs) that have been doped and adsorbed with Mn. These investigations are made possible by using the non-equilibrium Green’s function (NEGF) formalism in conjunction with Density Functional Theory (DFT). We have scrutinized the electronic structures of six different models, and have chosen two for a deeper exploration of its’ transport characteristics. Our computational findings highlight an unusual occurrence where a Mn atom substitutes a B atom in ZBNNRs, resulting in ZB(Mn)NNRs that exhibit significant Giant Magnetoresistance (GMR) and Rectification ratio (RR) - peaking at 106 and 105 respectively, along with the presence of negative differential conductance (NDC) effects. The detected GMR, NDC, and rectification characteristics in ZB(Mn)NNRs offer an optimistic outlook for the conceptualization of future nanodevices.

DFT investigation of hydrogenated cove-edged boron nitride nanoribbons for resonant tunneling diodes application

The cove-defect is found to improve the stability of the nanoribbons through bond length reconstructions at the cove-edge. Density functional theory (DFT) and non-equilibrium Green’s function (NEGF)-based first principles calculations are used to examine the structural, electronic, and quantum transport aspects of the hydrogenated cove-edge defective zigzag boron nitride nanoribbons (ZBNNRs). The additional electronic states, originated by dangling bonds at the cove-edges, exist across the Fermi level making these structures purely metallic. Additionally, with high peak-to-valley current ratios (PVCR), the quantum transport properties’ negative differential resistance (NDR) features are obtained. The highest PVCR is calculated to be 3.60 × 1016. The presented cove-edge defects can have a lot of potential for ultra-scaled devices including resonant tunnel diodes (RTDs), memory, and nanoswitches, according to the NDR phenomenon discovered in cove-edge ZBNNRs.

A DFT Based Approach for NO2 Sensing Using Vander Wall Hetero Monolayer

In the present study, two-dimensional (2-D) pristine and distorted hexagonal Zig-Zag Boron Nitride nano-ribbon (h-BNNR) has been used as a gas sensing material to detect Nitrogen dioxide (NO2). Distorted structures such as Al-doped, P-doped, and Stone–Wales defected structures are considered here as an electro-sensing material. The First principle density functional theory (DFT) computations-based ab initio approach has been used to investigate the electrochemical properties of pristine and distorted h-ZBNNR in presence of NO2. Upon NO2 adsorption, the conduction band/valance band and energy gap of the ribbon are decreased significantly. An increase in the transmission of electrons has been observed in increasing the bias voltage. Extensive simulations using Quantum wise have been done to validate the efficacy of the proposed gas sensor.

Electronic and optical properties of boron nitride nanoribbons exploiting DFT

We have used density functional theory and the SIESTA code to investigate the electronic bandgap and optical spectra of zigzag boron nitride nanoribbons n-ZBNNRs (n = 18, 22, 26, 30). The electronic structure of the simulated nanoribbons reveals that they are semiconductors with a bandgap of 4.87–4.95 eV. For energies greater than 5 eV, the real part of the dielectric function suggests that ZBNNRs are negative refractive index materials. n-ZBNNRs also have a lower static refractive index than armchair graphene nanoribbons. The fundamental reason is that the boron nitride nanoribbons have more localized electrons. The optical absorption of n-ZBNNRs (n = 18, 22, 26, 30) is anisotropic for the x, y, and z polarizations as well. Moreover, Eoptical gap18-BNNRs = 4.95 eV, Eoptical gap22-BNNRs = 4.94 eV, Eoptical gap26-BNNRs = 4.92 eV, and E optical gap30-BNNRs = 4.87 eV. The maximum optical extinction occurs at E ≈ 6–7 eV for the y polarization and E ≈ 5–6 eV for the z-direction. Besides, by around 6 eV for the y polarization (and 5 eV for the z polarization), σ is almost 1500 Ω−1 cm−1 (and 860–1500 Ω−1 cm−1). The imaginary part of the optical conductivity indicates that for the low energy range, n-ZBNNRs (n = 18, 22, 26, 30) supply the conditions of the transverse-electric mode existence. In addition, for $$E_{y} \, > \,6$$ eV and $$E_{x} \, > \,5$$ , n-ZBNNRs (n = 18, 22, 26, 30) support the transverse-magnetic plasmons.

Giant Magnetoresistance and Rectification Behavior in Fluorinated Zigzag Boron Nitride Nanoribbon for Spintronic Nanodevices

In the present work, the spin-polarized structural and electronic properties of fluorine (F) passivated zigzag boron nitride nanoribbons (ZBNNRs) at the selective boron (B) and nitrogen (N) edge atoms are investigated. This study is based on the density functional theory (DFT) along with non-equilibrium Green function (NEGF) formalism. Our study predicts that half-metallic property can be obtained in ZBNNRs via F passivation at selective edges. The F-passivated ZBNNRs are found to be structurally stable in both non-magnetic as well as magnetic ground states irrespective of their width. Hence, the transport properties of F-passivated ZBNNRs are also studied as fluorinated structures are reported to be more stable. The current-voltage characteristic of F-passivated ZBNNRs based devices exhibit the perfect spin-filter characteristics with magnificently high spin-filtering efficiency (SFE) even under a low bias. It is worth mentioning here that giant magnetoresistance resistance (GMR), and rectification ratio of the order of 10⁸and 10⁵ have also been observed for F-BN-F devices. This is because dangling bonds break the edge states' symmetry and induce some localized states, which suppress the electron transmission and reduce the current. The observed perfect spin-filtering characteristics, GMR, and rectifying characteristics suggest that Fpassivated ZBNNRs have immense potentials to be deployed for nanoscale spintronic devices.

Zn-Passivated Zigzag Boron Nitride Nanoribbons for Perfect Spin-Filtering and Negative Differential Resistance Based Devices

The spin polarized structural, electronic, and transport properties of Zn-passivated zigzag boron nitride nanoribbons (ZBNNRs) at the selective boron and nitrogen edge atoms along with H-passivation are investigated. Present density functional theory (DFT) based studies predict that half-metallic property can be obtained in ZBNNRs via selective Zn and H-passivation. The spin active most stable structure of Zn-passivated ZBNNRs is H-BN-Zn irrespective of ribbon width. The current-voltage characteristics of the Zn-passivated ZBNNRs device exhibit the perfect spin-filter characteristics with magnificently high spin-filtering efficiency even under a low bias. Interestingly, the negative differential resistance (NDR) with a large <inline-formula><tex-math notation="LaTeX">$I_{P}/I_{V}$</tex-math></inline-formula> (peak-to-valley current ratio (PVCR)) of the order of <inline-formula><tex-math notation="LaTeX">$10^{3}$</tex-math></inline-formula> has also been observed for Zn-BN-H due to spin-up current component. This is because the dangling bonds at the edge atoms break the edge states and stimulates multiple local states, which prevents electron transfer and reduces current to get a better <inline-formula><tex-math notation="LaTeX">$I_{P}/I_{V}$</tex-math></inline-formula> ratio. The observed perfect spin-filtering characteristics and NDR effect suggest that Zn-passivated ZBNNRs have immense potentials to be deployed for nanoscale spintronic devices.

Selective Edge-Hydrogenated Zigzag Boron Nitride Nanoribbons for Giant Magnetoresistance and Rectifying Behavior

The structural stability, spin-polarized electronic and transport properties of edge-hydrogenated zigzag boron nitride nanoribbons (ZBNNRs) are investigated using density functional theory (DFT) combined with a non-equilibrium Green’s function (NEGF) approach. The considered structures are observed to be energetically stable in the magnetic ground state. The calculated spin-dependent transport properties indicate that a selective-edge hydrogenated ZBNNR device shows bipolar spin filter characteristics. Interestingly, high spin giant magnetoresistance (GMR) and a rectification ratio (RR) are observed of the order of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> and 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> , respectively. The observed GMR and rectification behavior in edge-hydrogenated ZBNNRs have potential applications for designing future spintronic nanodevices.

First-principle investigations of negative differential resistance in zigzag boron nitride nanoribbons

This work investigates the structural stability, electronic and transport properties of zigzag boron nitride nanoribbons (ZBNNRs) with hydrogenation/fluorination by using density functional theory (DFT) along with non-equilibrium Green’s function (NEGF) approach. The study reveals that ZBNNRs exhibit metallic to semiconducting transition via selected edge fluorination. Interestingly, edge fluorinated ZBNNRs demonstrate high structural stability due to the higher electronegativity of fluorine. It is also revealed that negative differential resistance (NDR) has also been observed for edge fluorinated two terminal devices with enormously high peak to valley current ratio (PVCR) of the order of 1 0 11 . We have also investigated the gate controllable current–voltage (I–V) characteristics of three terminal ZBNNRs field effect transistor (FET). The selective structures exhibit excellent gate controllability which can tune the observed PVCR. Our findings indicate the potential of fluorinated ZBNNRs towards upcoming ultra fast switches, rectifiers and oscillators etc. • This work investigates the structural stability, electronic and transport properties of zigzag boron nitride nanoribbons (ZBNNRs) with hydrogenation/ fluorination by using density functional theory (DFT) along with non-equilibrium Greens function (NEGF) approach. • It is revealed that negative differential resistance (NDR) has also been observed for edge fluorinated two terminal devices with enormously high peak to valley current ratio (PVCR) of the order of 10 11 . We have also investigated the gate controllable current–voltage (I–V) characteristics of three terminal ZBNNRs field effect transistor (FET). • The selective structures exhibit excellent gate controllability which can tune the observed PVCR. • Our findings indicate the potential of fluorinated ZBNNRs towards upcoming ultra fast switches, rectifiers and oscillators etc.

First-Principles Investigations of N-Vacancy Induced Zigzag Boron Nitride Nanoribbons for Nanoscale Resonant Tunneling Applications

First-Principles Investigations of N-Vacancy Induced Zigzag Boron Nitride Nanoribbons for Nanoscale Resonant Tunneling Applications

Thermoelectric properties study on the BN nanoribbons via BoltzTrap first-principles

Thermoelectric materials have attracted the attention of scientists because they directly convert waste heat of electric energy into valuable electrical energy. In recent years, the boron nitride structure has attracted much attention due to its thermoelectric properties and environmental friendliness. In this paper, the thermoelectric properties of boron nitride nanoribbons were simulated and analyzed, discovering that the figure-of-merit (ZT) value of armchair boron nitride nanoribbons is much better than that of zigzag boron nitride nanoribbons. Subsequently, we discuss the bandwidth effects and edge chirality on two important thermoelectric properties, Seebeck coefficient and ZT. Although edge passivation has been carried out, different edge chiralities still have a significant impact on carrier transport. The development of boron nitride-based materials will clarify their potential for developing high performance next generation thermoelectric devices.

Boron nitride nanoribbons with single vacancy defects and doped with 3d transition metals: A first-principles study

The structural stability, together with the electronic and magnetic properties of zigzag boron nitride nanoribbons (ZBNNRs) with single vacancy defects and doped with ten 3d transition metal (TM) species was investigated using spin-polarized density functional theory (DFT). The results on the formation energy show that the structural stability of the ZBNNRs with single vacancy defects decreases significantly when compared to pristine nanoribbons. Moreover, the ZBNNRs with the N-site vacancy defects are generally more stable than those with the B-site ones. By conducting the ab initio molecular dynamic simulations, the ZBNNRs with the 4B-site or 4N-site vacancy defects are both shown to be stable at room temperature. Among the BN nanoribbons doped with ten different TM ions, the structural stability of the Sc-, Ti-, and V-doped systems appears to be improved, whereas the Cr-, Mn-, Fe-, Co-, Ni-, Cu-, and Zn-doped ZBNNRs are unstable when compared to the pristine ZBNNRs. The vacancy defects and the substitutional doping via 3d TM atoms, excluding the scandium atom, exhibit a magnetic effect in non-magnetic ZBNNRs. The difference charge density diagrams indicate that during the doping process, the electrons mainly transfer from the transition metal ions to their three adjacent N atoms.

Electronic properties of zigzag boron nitride nanoribbons periodically embedded with four- and eight-membered rings

ABSTRACTWe systematically studied the electronic properties of zigzag boron nitride nanoribbons periodically embedded with four- and eight-membered rings (new ZBNNRs) and the influence of vacancies on the electronic properties. The results reveal that the band gap of the new ZBNNRs is greatly reduced, down to a range of 3.830–3.995 eV, enabling the allotropes to display semiconductor properties and satisfying the requirements of the third-generation semiconductor bandgap width, and can provide high-quality materials for the preparation of third-generation semiconductor nanodevices. Second, although the vacancy has not changed the semiconductor characteristics of the new ZBNNRs, the band-gap bandwidth will be reduced to some extent due to the difference in vacancy position and electronic state.

Magnetic and electronic properties of zigzag BN nanoribbons with nonmetallic atom terminations: A first-principles study

The boron nitride (BN) nanosheet is an isostructural analog of graphene and can be viewed as the structure that C atoms in graphene are replaced with alternating B and N. The easily modulated band-gap of BN nanosheet by simply passivating its edge(s) makes it is promising for many potential applications in nanodevices and nanoelectronics. We further systematically theoretically study the magnetic and electronic properties of passivated-ZBNNR by nonmetallic atom(s), here. According to our calculations, all considered structures show magnetic feature, and the ZBNNRs can be metal or half-metal or semiconductor depending on the termination details. The great application-potential of the passivated-ZBNNRs is further confirmed based on our results.

Electronic and magnetic properties of Fe-doped narrow zigzag boron nitride nanoribbons

The electronic structures and magnetic properties of single Fe-doped in the different substitutional sites for narrow zigzag boron nitride nanoribbons are studied based on density functional theory. By examining the total energy and formation energy, we predict that doping Fe in the substitutional 4B-site is more favorable than other sites in our calculated narrow zigzag boron nitride nanoribbons. The behavior of doping single Fe in the zigzag boron nitride nanoribbons drives the system to tend to show a spin polarized state, and the induced magnetic moment depends on the substitutional sites. The calculated electronic structures show that Fe-doped narrow zigzag boron nitride nanoribbon becomes a semiconductor with a direct energy gap, while the pristine boron nitride nanoribbon is an insulator with an indirect wide energy gap. The molecular dynamic simulation results predicate that single Fe-doped narrow zigzag boron nitride nanoribbons can exist stably under the realistic environment.

Effect of strain on the mechanical and electronic properties of h-BN nanoribbons with 558 linear defect

Abstract We have applied first principles calculations to investigate the effect of the uniaxial tensile strain on the mechanical and electronic properties of hexagonal zigzag boron nitride nanoribbons (h-ZBNNRs) with embedded 558 linear defect (LD). Our calculations indicate that 558-LD induces a larger decrease in the energy gap if compared to pristine (h-ZBNNRs). In addition, we have shown that the effect of strain displays most efficiency to tune the energy gap than on pristine 558-LD. Also, we have obtained the Young's modulus through two different approaches.

Magnetic and electronic properties of zigzag boron nitride nanoribbons with nonmetallic atom asymmetric passivation

In this paper, we modify the magnetic and electronic properties of zigzag boron nitride nanoribbons (ZBNNRs) with asymmetric edge passivation nonmetallic (NM) atoms. The 12 possible cases of the XN-ZBNNR-BY systems (X, Y=O, S, F or P) can be divided into four types: the PN-ZBNNR-BY (Y=O, S or F), SN-ZBNNR-BY (Y=F, O or P), ON-ZBNNR-BY (Y=F, S or P) and FN-ZBNNR-BY (Y=O, P or S). The results show that all four types of the XN-ZBNNR-BY systems display the metallic properties in both channels mainly due to termination atoms O, S and P with 4, 4 and 3 p electrons, but only the ON-ZBNNR-BY (Y=F, S or P) systems display the magnetic properties. Furthermore, the total magnetic moments of the ON-ZBNNR-BY (Y=F, S or P) systems are contributed constantly by the termination O atoms and edge N atoms, regardless of termination Y atoms. Finally, the contributions to the total magnetic moments are very small for the inner N and B atoms.

Melting process of zigzag boron nitride nanoribbon

Zigzag hexagonal boron nitride nanoribbon (h-BNNR) model in two-dimensional (2D) case is studied via molecular dynamics simulation. The model contains 10000 atoms interacted via the Tersoff bond order potential. Temperature is increased from 50 K to 7000 K in order to see the evolution of various thermodynamic quantities, structural characteristics, and the occurrence of liquid-like atoms upon heating to a molten state. Lindemann criterion for 2D case is calculated and used to observe the appearance of liquid-like atoms. Atomic mechanism is analyzed on the basis of the occurrence/growth of liquid-like atoms, the formation of clusters, coordination number, and ring statistics. The largest cluster does not contain all liquid-like atoms in the whole range of temperature in this study. After reaching a peak at the melting point of this model, the largest cluster slightly decreases indicating that the single largest cluster of liquid-like atoms tends to form a ring-like 2D liquid zigzag h-BNNR. Armchair h-BNNR is studied to compare with zigzag h-BNNR model. The melting point of armchair h-BNNR (3600 K) is close to the experimental results of hexagonal boron nitride (h-BN) (from 2800 K to 3600 K) whereas the one of zigzag h-BNNR (4522 K) is higher than that of armchair h-BNNR and plane h-BN.

Spin-Polarized Transport Behavior Induced by Asymmetric Edge Hydrogenation in Hybridized Zigzag Boron Nitride and Graphene Nanoribbons

We fused zigzag graphene to boron nitride nanoribbons by gradually doping C atoms at only one edge of the ribbons to design a hybridized ZBxNyCz (x + y + z = 12) structure. To create asymmetric edge hydrogenation, the ZBxNyCz ribbons were monohydrogenated (N–H) at one edge and dihydrogenated (C–H2) at the opposite edge, and the structure was subsequently labeled as H-ZBxNyCz-H2. On the basis of density functional theory and non-equilibrium Green’s function, our simulation revealed that H-ZBxNyCz-H2-based devices present a variety of abnormal spin-polarized transport properties. When the value of x and y in the H-ZBxNyCz-H2 structure is not equal (i.e., z is an odd number), the spin-polarized currents are restricted, regardless of their ferromagnetic (FM) or anti-ferromagnetic (AFM) state. When x is equal to y (i.e., z is an even number), the H-ZBxNyCz-H2 structure exhibits negative differential resistance and spin-filtering features in the FM state. Conversely, in the AFM state, the spin-polarized currents of the structure exhibit an exceptional oscillation effect with spin polarization as high as 100% at certain bias voltages. By adjusting the width of graphene and the spin states, the resulting hybridized H-ZBxNyCz-H2 structure can be potentially applied to the fabrication of spin nanodevices with exotic functionalities.

Magnetic and electronic properties of zigzag boron nitride nanoribbons with nonmetallic atom terminations from first-principles

In this paper, we modify the magnetic and electronic properties of zigzag boron nitride nanoribbons (ZBNNRs) by adopting the method of edge-modification, which is achieved by passivating the edges of ZBNNRs with nonmetallic (NM) atoms H, O, S, F and P. Five different cases for XN + N-ZBNNR-B + BH, where X = H, O, S, F and P nonmetallic (NM) atoms are studied systematically. The calculated results indicate that for only X = P, the XN + N-ZBNNR-B + BH displays the half-metallic feature while the others exhibit metallic properties. The metallic feature of the XN + N-ZBNNR-B + BH (X = H, O, S, and F) systems is due to the contribution of both termination atoms and edge atoms to the total density of states at the Fermi level. The XN + N-ZBNNR-B + BH (X = H, O, S, F and P) are all magnetic materials. In addition, the half-metallic feature of the PN + N-ZBNNR-B + BH material is a new style of nano-material and a perfect candidate for spintronic applications.

Enhancement of the surface reactivity of zigzag boron nitride nanoribbons by chlorine gas decoration: A computational study

In this study, we explored the field emission and chlorine sensing mechanisms of zigzag boron nitride nanoribbons (ZBNNRs). First principle calculations were used to investigate the surface reactivity of ZBNNRs within the framework of the density functional theory based on the local density approximation and generalized gradient approximation. Six different possibilities were considered for chlorine-gas termination and adsorption on ZBNNRs. The band gap of the ZBNNRs decreased monotonically as the ribbon width increased. The charges on the functional groups and corresponding bond lengths, i.e., B(N)-X and X-X (Cl-Cl), were dependent on the adsorption sites (B or N edge) and the types of functional groups, but independent of the ribbon width. Chlorine gas (Cl2) induced electrons into the conduction band and their consequent electronic states over the Fermi level enhanced the electrical conductivity. Transmission spectra demonstrated the spin-dependent electron tunneling from the valence band to the conduction band. Charge density analysis indicated the charge trapping behavior of the ZBNNRs. Cl2 introduced excess negative charges onto the active surfaces of the ZBNNRs to enhance their surface reactivity. Therefore, Cl2-decorated ZBNNRs can be employed as Cl2 sensors and they may also be useful in field emission applications.