The Nature of Radiative Transitions in O-Doped Boron Nitride Nanotubes

Abstract

Recent measurements on cathodoluminescences spectra of natural and isotope-substituted boron nitride nanotubes (BNNTs) surprisingly suggest the existence of pronounced radiative transitions in BN tubes, which are possibly induced by the oxygen substitutional impurities of the samples. [Han, W. Q. et al. Nano Lett. 2008, 8, 491] However, the structural pattern of the O-doped BN tube is unknown, as a result, how does the substitutional impurity in BNNT contribute to the observed radiative transitions is still a puzzle. Using first-principle calculations, we predict a novel, stable O-doped BNNT configuration. Such a structure contains one B(3)O(6) group, which is similar to the structural unit of boron oxide. Our calculations demonstrate that this type of O substitutional impurity can result in some donor-like gap states in the electronic structure and lead to the significant changes on the optical properties of BNNTs. The vibrational properties of the O-doped BNNT and boron oxide are also investigated. Our work elucidates the origins for experimental findings and provides a strong theoretical evidence on the existence of O substitutional impurity-induced radiative transitions in BNNT systems.

Oxidation fracturing of the graphitic BN sheet

“…This is in agreement with the results obtained by Arenal et al [22]. In addition, Gou et al [23] also found that the local structure of B 3 O 6 group is emerged by the extra geometrical constraint, which may be considered as a proceeding species during the BN synthesis process. To the best of our knowledge, there is no investigation on this issue of the oxidation of graphitic BN sheet though new theoretical [23] and experimental [24] investigations emerge.…”

“…It is just a segment of the boroxol groups B 3 O 6 described in Ref. [23], which is a common boron oxide used frequently in the synthesis of BN nanotubes [22]. The uncompleted B 3 O 6 structure, i.e., B 3 O, behaves very unstable with strong oxidation.…”

“…In addition, Gou et al [23] also found that the local structure of B 3 O 6 group is emerged by the extra geometrical constraint, which may be considered as a proceeding species during the BN synthesis process. To the best of our knowledge, there is no investigation on this issue of the oxidation of graphitic BN sheet though new theoretical [23] and experimental [24] investigations emerge. Therefore, understanding a complete of this underlying oxidation cutting mechanism is of paramount importance to on going investigations in the graphitic BN sheet and its future applications.…”

Geometric and Spectroscopic Properties of Carbon Nanotubes and Boron Nitride Nanotubes

“…For reason, BNNTs with the small diameter were suggested as an aspirant for a synthetic aquaporin-1 water channel [57]. A variety of subjects of BNNTs have been investigated by theoretical methods, including hydrogen storage [60,61,62,63,64,65,66], magnetism [67,68,69,70,71,72,73], phonon characteristics [74,75,76], stability [77,78,79], molecular dynamics [80,81,82,83], field-electron emission [84], scanning tunneling microscopy simulation [85], electron transport [86], symmetry breaking [87], work function [88], spin-splitting [89] and quantum computing [90,91]. …”

“…Therefore, the calculated values of the electronic band gabs for the nanotubes might be reasonable. Various methods have been developed to tune the electronic structure of BNNTs is nicely discussed by Chunyi Zhi et al [57], for instance, applying electric field [133,134,135,136,137,138] or strain [139], or chemical methods, like doping [140,141,142,67], introducing defects [143,144,145] or surface modification [60,146,147]. The methods and species chosen are summarized in Table 2 in Ref.…”