Quantum-Chemical Modeling of the Electronic Structure of Single-Walled Janus Nanotubes in an Electric Field

Single-walled ultrashort (BN–C) Janus nanotubes of (n,0) and (n,n) chirality were studied by the DFT6-31G/B3LYP method. It is shown that these molecular systems are stable with respect to dissociation into constituent parts. The (BN–C) Janus nanotubes possess emission molecular orbitals with electron density localized in the end regions of the nanotubes. The energy of the emission molecular orbitals is sensitive to a uniform constant electric field. The critical values of the electric field strength for the appearance of emission current were estimated qualitatively. The emission properties of (BN–C) Janus nanotubes depend on the direction of the external electric field strength vector. The best emission properties in an electric field are inherent in the “transverse” (BN–C) Janus nanotubes, whose peri-positions are occupied by pyrrole nitrogen atoms and the electric field strength vector is directed along the cylindrical axis of the nanotube to the carbon fragment of the nanostructure.