The structure, stability, and electronic properties of ultra-thin BC2N nanotubes: a first-principles study

Abstract

Rapid developments of the silicon electronics industry have close to the physical limits and nanotube materials are the ideal materials to replace silicon for the preparation of next generation electronic devices. Boron-carbon-nitrogen nanotubes (BCNNT) can be formed by joining carbon nanotube (CNT) and boron nitride nanotube (BNNT) segments, and BC2N nanotubes have been widely and deeply studied. Here, we employed first-principles calculations based on density function theory (DFT) to study the structure, stability, and electronic properties of ultra thin (4 Å diameter) BC2N nanotubes. Our results showed that the cross sections of BC2N nanotubes can transform from round to oval when CNT and BNNT segments are parallel to the tube axis. It results when the curvature of BNNT segments become larger than CNT segments. Further, we found the stability of BC2N nanotubes is sensitive to the number of B-N bonds, and the phase segregation of BNNT and CNT segments is energetically favored. We also obtained that all (3,3) BC2N nanotubes are semiconductor, whereas (5,0) BC2N nanotubes are conductor when CNT and BNNT segments are perpendicular to the tube axis; and semiconductor when CNT and BNNT segments are parallel to the tube axis. These electronic properties are abnormal when compared to the relative big ones.

Semiconducting to metallic transition in CX(BN)Y nanotubes: effects of C stripes in BN basis

“…Among these, one (type I) showed metallic characteristics, whereas another (type II) was a semiconductor. In addition to this, other possible atomic arrangements and chemical compositions (BCN, B3C2N3, BC4N, and B5C2N5) of B − C − N tubular structures can also be found in the literature [9,18,20,26,37,42,43,60,68,75,77,86]. By virtue of these flexible electronic properties (from metallic to semiconducting), these materials have several potential applications such as electrical conductors [6,30,36,81], capacitors, light-emitting diodes, optical devices [6,18,29,30,55], and gas adsorption devices [7,33].…”

“…These are: (i) stoichiometry, (ii) diameter, (iii) chirality, and (iv) atomic distribution of B, C, and N atoms in the hexagonal network. In light of the theoretical results for the same stoichiometry, BXCYNZ nanotubes can show different diameters, chiralities, and atomic arrangements [22,26,52,56,77,78]. That being said, some studies have indicated that the electronic band gap values can be altered according to nanotube chirality and diameter [26,55,56].…”

“…An important member of the BXCYNZ family is the BC2N nanotube [2,6,3,39,55,77]. Experimental and theoretical results have shown that this nanotube is the most energetically favorable structure [3], with semiconducting character, the gap being lower than that of BN nanotube.…”