THEORETICAL STUDY OF STRUCTURAL, ELECTRONICS AND THERMOELECTRIC PROPERTIES OF h-BN NANOTUBE ACTIVATED BY Fe IONS

Actually, Boron Nitride nanotubes (BNNT) have received great interest as material dedicated to many applications such as electronic and thermoelectrical devices.This work is a theoretical study of the structural, electronic and thermic transport properties of pure and iron (Fe) doped Boron Nitride nanotubes (BNNT) in its hexagonal phase (h-BN).This theoretical study was performed with the CRYSTAL program (www.crystal.unito.it)providing crystalline orbitals built on localized orbitals at the DFT (B3LYP hybrid hamiltonian) level of approximation.We have shown that Fe-doping nanotubes could behave as narrow bandgap semiconductors, the presence of Fe atoms modifying the gap value because of the presence of states participating to the thermoelectrical transport.Our calculations show that the undoped nanotubes are ceramic materials with a large band gap around 6 eV while this latter value can be divided by 2 when the nanotube is doped by Fe.The related Seebeck coefficient, and electrical and thermal conductivity properties allow to deduce the values of the figure of merit ZT.Obtained results indicate that BNNT can be considered promising as thermoelectrical materials.