DFT calculation for graphene/hexagonal-boron-nitride nanoisland applicate in photonic device

Abstract

In the present study, density function theory (DFT) tool is used to compute structural, electronic and optical properties for hexagonal-boron-nitride (h-BN) nanosheet, perfect and defected (one carbon atom remove) graphene (G)/boron-nitride nanoisland. The basis set 6-31G is utilizing in a present study with hybrid function (B3LYP). Relaxation calculation is showing that all bond length between atoms are agreement with theoretical and experimental measurements, also the surface of all systems was remain in plane form. Energy gap calculation shows that a h-BN nanosheet has insulator nature. Doping h-BN by carbon (C) and defected (by remove one carbon atom) the energy gap is modifying and reduce from (6.006) to (3.464 and 1.569) eV, respectively. In the other hand, doped and defected mechanism enhance the conductivity of h-BN nanosheet. UV-Visible calculation is showing that h-BN absorbing in the ultra-violet region, doped and defected nanoisland were absorbed light in the visible region of electromagnetic radiation and shifted to long wavelength (Low energy). Fourier transformation-infrared radiation (FT-IR) calculations are showing that all active group are appearing like (C-C), (C-B), (C-N), (B-H) and (N-H) and approximately agreement with experimental measurements. Light harvesting efficiency (LHE) calculation is concluding that h-BN/G nanoisland have high ability to harvest light compared with h-BN nanosheet and defected h-BN/G nanoisland. Results show that higher occupied molecular orbital (HOMO) is being distributed above minimum conduction band (CBM) of titanium dioxide (TiO2), and lower unoccupied molecular orbital (LUMO) is being populate below iodine/ tri-iodine (I/I3) electrolyte. Meanwhile, all nanostructure is having ability to generate pair electron-hole. Finally, results show that the measurements are indicating that it is possible to apply the composites under study in the field of photonic devices especially in solar cell field.

Density functional theory studies on graphene/h-boron nitride hybrid nanosheets for supercapacitor electrode applications

“…In the meantime, Abed et al showed that charge redistribution on doping graphene into the h-BN nano island resulted in localization of electron cloud density at the doped region, and our result matches their observation. 65…”