Effect of carbon doping on electromechanical response of boron nitride nanosheets

Abstract

The electromechanical response of hexagonal-boron nitride nanosheets (h-BNSs) was studied via molecular dynamics simulations (MDS) with a three-body Tersoff potential force field using a charge-dipole (C-D) potential model. Carbon (C)-doped h-BNSs with triangular, trapezoidal and circular pores were considered. The elastic and piezoelectric coefficients of h-BNSs under tension and shear loading conditions were determined. The induced polarization in h-BNSs was found to depend on the local arrangement of C atoms around B and N atoms, and the polarization increases if C atoms are surrounded by N atoms. This is attributed to the generation of higher dipole moments due to C–N bonds compared with C–B bonds. At ∼5.5% C-doping concentration, the axial piezoelectric coefficient of doped h-BNSs with triangular and trapezoidal pores increased by 18.5% and 3.5%, respectively, while it reduced by 22.5% in the case of circular pores compared to pristine h-BNS. The shear piezoelectric coefficient of C-doped h-BNSs with triangular and trapezoidal pores increased by 20.5% and 1%, respectively, while it reduced by 7% in case of circular pores. Young’s moduli of C-doped h-BNSs with triangular, trapezoidal and circular pores increased by 9%, 7.5% and 5.5%, respectively, due to the C–C bonds being stronger than all other bonds. The respective improvements in shear moduli are 8.5%, 5% and 5%. The elastic and piezoelectric properties of armchair h-BNSs were found to be higher than zigzag h-BNSs. The results also reveal that the piezoelectric coefficient increases as doping increases; it reaches its maximum value around 0.41 C m−2 at 12.6% C-doping concentration and then starts decreasing. The present work shows that we can engineer the electromechanical response of h-BNSs via novel pathways such as different types and size of pores as well as C-doping concentration to suit a particular nanoelectromechanical systems (NEMS) application.

Adsorption and desorption behavior of titanium-decorated polycrystalline graphene toward hydrogen storage: a molecular dynamics study

“…To accurately perform MDS of hydrogen adsorption on PGs decorated with Ti atoms, the interatomic interactions of PGs atoms are described using the Tersoff potential [49], which was applied successfully in previous studies [50,51]. The interactions between carbon atoms of PGs and Ti atoms are described using the Lennard-Jones (LJ) 12-6 potential.…”

Piezoelectric and dielectric constants of topologically defected boron nitride nanotubes

“…Besides the SW defect, carbon doping is known to improve the elastic modulus and piezoelectcity of h-BNs providing a room for defect engineering. 32 To apply the BNNTs to nanogenerators, nanoelectronics, and electroactive nanocomposites, electromechanical constitutive laws must be provided. Thus, an investigation of the piezoelectric and dielectric constants of BNNTs according to their intrinsic defects is imperative.…”

Molecular Dynamics Study of Anisotropic Shock Response in Mono- and Bicrystalline Boron Nitride Nanosheets: Implications for Shock-Resistant Solid-State Devices

“…The superior two-dimensional (2D) nanostructure of the hexagonal boron nitride nanosheet (BNNS) has attracted interest for its distinguished properties such as high Young's modulus, 1 quantum electronic transport, 2 tunable band gap, chemical resistivity, thermal stability even at higher temperature, 3 and tunable electromechanical properties. 4 It has a wide range of potential applications in reinforcing polymers, 5−7 drug-delivery vehicles and sensors, 8−10 energy storage, 11 solid devices in nanoelectronics, 12 and as a potential alternative to the traditional silicon-based semiconductor. 13 Similar to graphene, synthesizing 2D BNNSs with chemical vapor deposition (CVD) inevitably introduces various kinds of structural imperfections, such as boron (B) or nitrogen (N) single vacancies and divacancies, Stone−Wales defects (STW), rehybridization defects, and grain boundaries (GBs).…”

“…The research community has already explored defective BNNSs for developing applications that include ion separation, tailoring the properties of nanocomposites, 24,25 and for tuning the magnetic 26 and electromechanical properties. 4 Kumar and Parashar 27 studied the shielding effect provided by STW defect at the crack tip opening stresses in BNNSs. They predicted that the fracture toughness of BNNSs is significantly enhanced in the presence of STW defects.…”

“…The superior two-dimensional (2D) nanostructure of the hexagonal boron nitride nanosheet (BNNS) has attracted interest for its distinguished properties such as high Young’s modulus, quantum electronic transport, tunable band gap, chemical resistivity, thermal stability even at higher temperature, and tunable electromechanical properties . It has a wide range of potential applications in reinforcing polymers, − drug-delivery vehicles and sensors, − energy storage, solid devices in nanoelectronics, and as a potential alternative to the traditional silicon-based semiconductor …”