UV absorption in metal decorated boron nitride flakes: a theoretical analysis of excited states

ABSTRACT

The excited states of single metal atom (X = Co, Al and Cu) doped boron nitride flake (MBNF) B₁₅N₁₄H₁₄-X and pristine boron nitride (B₁₅N₁₅H₁₄) are studied by time-dependent density functional theory. The immediate effect of metal doping is a red shift of the onset of absorption from about 220 nm for pristine BNF to above 300 nm for all metal-doped variants with the biggest effect for MBNF-Co, which shows appreciable intensity even above 400 nm. These energy shifts are analysed by detailed wavefunction analysis protocols using visualisation methods, such as the natural transition orbital analysis and electron-hole correlation plots, as well as quantitative analysis of the exciton size and electron-hole populations. The analysis shows that the Co and Cu atoms provide strong contributions to the relevant states whereas the aluminium atom is only involved to a lesser extent.

KEYWORDS:

• Boron-nitride
• TDDFT
• excited state analysis
• NTO
• charge transfer

Acknowledgments

Siddheshwar Chopra acknowledges the National PARAM Supercomputing Facility (NPSF) of C-DAC, Pune, India, for providing the cluster computing facility. Felix Plasser acknowledges support from the VSC Research Center funded by the Austrian Federal Ministry of Science, Research, and Economy (bmwfw).

Disclosure statement

No potential conflict of interest was reported by the authors.