Tuning the optical response in carbon doped boron nitride nanodots

Mokkath, Junais Habeeb; Schwingenschlögl, Udo

doi:10.1039/c4tc01640h

Cited by 17 publications

(16 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Free valencies resulting from cutting the molecular cluster from the 2D BN are saturated with hydrogen atoms, what is a common practice in molecular fragmentation methods . It should be noted that the same approach was utilized for other types of h ‐BN 2D defects in a recent work of Mokkath and Schwingenschlögl and Reimers et al, as well as in a study of the doped graphene by Thakur et al…”

Section: Theoretical Methodsmentioning

confidence: 99%

“…Free valencies resulting from cutting the molecular cluster from the 2D BN are saturated with hydrogen atoms, what is a common practice in molecular fragmentation methods. [30] It should be noted that the same approach was utilized for other types of h-BN 2D defects in a recent work of Mokkath and Schwingenschlögl [25] and Reimers et al, [26] as well as in a study of the doped graphene by Thakur et al [31] Geometries of all the molecules under study were obtained by the optimization procedure on the DFT level with a dispersion-corrected B97-D3 functional [32,33] and TZVP [34] basis set (the def1 version). The examination of harmonic frequencies for the obtained structures was performed in order to confirm that the stationary points are indeed local minima on the potential energy hypersurface.…”

Section: Theoretical Methodsmentioning

confidence: 99%

“… from which the energy level of the C N impurity is estimated at about 2.3 eV. There also several theoretical studies of such defects, like the time‐dependent (TD) density functional theory (DFT) study of Mokkath and Schwingenschlögl of selected carbon defects or the work of Reimers et al Attaccalite et al employed the Bethe‐Salpeter equation to study excitations of four types of point defects (C N , V B , V N , and V BN ) and tentatively attributed the experimental 4 eV peak to the V B vacancy. A very recent theoretical and experimental study of Weston et al should also be mentioned here .…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Exploring point defects in hexagonal boron‐nitrogen monolayers

Korona

Chojecki

2019

Int J of Quantum Chemistry

View full text Add to dashboard Cite

A comprehensive theoretical study of selected point defects for a monolayer of hexagonal boron nitride (h‐BN) is presented. Two‐dimensional structures were simulated through large h‐BN molecular clusters and used to examine various defects, like: atom vacancies, atom substitutions, or distortions of the hexagonal lattice. Since carbon contaminations are very common in the h‐BN technology, a particular attention has been paid to carbon impurities. The calculations of IR spectra for the doped molecular clusters reveal the presence of additional frequencies, which in many cases correspond to defect‐bound modes. In particular, when two carbon atoms are close to each other, a localized stretching CC mode of a high intensity has been found, with a frequency value of about 100‐200 cm–1 higher than for collective BN stretch frequencies. Absorption UV‐Vis spectra obtained from time‐dependent density functional theory show that the inclusion of impurities results in an emergence of several low‐energy electronic excitations, from which some are localized on a defect, while other are delocalized. Energies of these excitations are strongly dependent on the defect type, and they range from about 0.7 to 6.1 eV for the lowest excitations. Based on UV‐Vis spectra we propose several candidates which could be responsible for the experimental 4 eV color band. These defects are built from two or four adjacent carbon atoms and have the lowest excitation ranging from 3.9 to 4.8 eV, which is strongly localized on the defect.

show abstract

Section: Theoretical Methodsmentioning

confidence: 99%

Section: Theoretical Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Exploring point defects in hexagonal boron‐nitrogen monolayers

Korona

Chojecki

2019

Int J of Quantum Chemistry

View full text Add to dashboard Cite

show abstract

“…Finally, with DFT we analyzed the mechanical properties of BCN systems. Previous calculations have revealed stressstrain relations [53], and how the band gap [54], work function [55], piezoelectric constants [56] and optical properties [57] change under applied strain. However, these studies considered various crystalline or highly ordered configurations of C, B, and N (including BN or C islands embedded into graphene or BN [58]); an investigation of mechanical properties and stability of the systems was not done for random configurations.…”

Section: Mechanical Properties Of Bcn Monolayermentioning

confidence: 99%

Substitutional carbon doping of free-standing and Ru-supported BN sheets: a first-principles study

Berseneva

Komsa

Vierimaa

et al. 2017

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

The development of spatially homogeneous mixed structures with boron (B), nitrogen (N) and carbon (C) atoms arranged in a honeycomb lattice is highly desirable, as they open the possibility of creating stable two-dimensional materials with tunable band gaps. However, at least in the free-standing form, the mixed BCN system is energetically driven towards phase segregation to graphene and hexagonal BN. It is possible to overcome the segregation when BCN material is grown on a particular metal substrate, for example Ru(0 0 0 1), but the stabilization mechanism is still unknown. With the use of density-functional theory we study the energetics of BN/Ru slabs, with different types of configurations of C substitutional defects introduced to the h-BN overlayer. The results are compared to the energetics of free-standing BCN materials. We found that the substrate facilitates the C substitution process in the h-BN overlayer. Thus, more homogeneous BCN material can be grown, overcoming the segregation into graphene and h-BN. In addition, we investigate the electronic and transport gaps in free-standing BCN structures, and assess their mechanical properties and stability. The band gap in mixed BCN free-standing material depends on the concentration of the constituent elements and ranges from zero in pristine graphene to nearly 5 eV in free-standing h-BN. This makes BCN attractive for application in modern electronics.

show abstract

“…It has been experimentally shown that boron nitride nanosheets can be used as deep-UV photodetectors 8 . Carbon doping has been tested to tune the optical response of boron nitride nanodots 9 .…”

Section: Introductionmentioning

confidence: 99%