Electronic and thermoelectric properties of zigzag and armchair boron nitride nanotubes in the presence of C island

Electronic and thermoelectric properties of zigzag and armchair single wall Boron Nitride Nanotubes (SWBNNTs) are investigated with and without one hexagonal carbon island by using first density functional theory (DFT), which is carried out in the Quantum Espresso packages. The ZSWBNNTs and ASWBNNTs show semiconductor and insulator behaviors, respectively along with a direct bandgap at the Γ point in the pristine cases. The obtained results display that this island is affected and altered to the electronic and thermoelectric properties of all systems. The behaviors of all systems are turning to semiconductor and the electronic band gaps are reduced with the C island which enables to use these doped materials in various applications. Meanwhile, the thermoelectric parameters, such as Seebeck coefficient (S), thermoelectric figure of Merit (ZT), phonon thermal conductance (Kph), electrons thermal conductance (Ke), and thermal conductivity of all systems are calculated and studied with and without the C island. The results show that all these thermoelectric properties are related directly to the diameter of the ZSWBNNTs and ASWBNNTs.