Sergey A. Malykhin | Searcharxiv

arXiv2020

Coulomb blockade in field electron emission from carbon nanotubes

We report the observation of Coulomb blockade in field electron emission (FE) from single-wall carbon nanotubes (SWCNTs), which is manifested as pronounced steps in the FE current-voltage curves and oscillatory variations in the energy distribution of emitted electrons. The appearance of the Coulomb blockade is explained by the formation of nanoscale protrusions at the apexes of SWCNTs due to the electric field-assisted surface diffusion of adsorbates and carbon adatoms. The proposed adsorbate-assisted FE mechanism is substantially different from the well-known resonant tunneling associated with discrete electronic states of adsorbed atoms. The simulations based on the Coulomb blockade theory are in excellent agreement with the experimental results. The SWCNT field emitters controlled by the Coulomb blockade effect are expected to be used to develop on-demand coherent single-electron sources for advanced vacuum nanoelectronic devices.

cond-mat.mes-hall↗

arXiv2019

Cathodoluminescence of CdZnSSe crystals synthesized in 19th century bead glass

The article presents an experimental investigation of band-edge cathodoluminescence of CdZnSSe crystals that nucleated and grew in silicate glass melt during its production. We have studied Zn-rich red glass made for manufacture of seed beads in the 19th century and found it to contain CdZnSSe crystals. Due to colloidal staining using the CdZnSSe crystallites embedded in glass, glass makers were enabled to produce lustrous red glass that, as we presently know, manifests bright luminescence. The CdZnSSe crystallites exhibit intense band-edge cathodoluminescence both at room temperature and at liquid nitrogen temperature. We have found the band-edge cathodoluminescence of these crystals to peak in the range from 2.00 to 2.03 eV at 300 K and from 2.02 to 2.06 eV at 80 K. We have also estimated the value of the band gap derivative d$E_g$/d$T$ in the interval from 80 to 300 K and found it to lie in the range from $-2.5 \times 10^{-4}$ to 0 eV/K. CdZnSSe crystals in glass demonstrate high temperature and temporal stability. The glass-crystal composite on their basis is resistant to the electron-beam irradiation and long-term weathering. Possible applications of this composite in modern technologies, and processes and components that might be used for making glass stained with CdZnSSe in the past are also discussed.

cond-mat.mtrl-sci↗