Boron-phosphorous doped graphyne: A near-infrared light absorber

Barnali Bhattacharya,Jyotirmoy Deb,Utpal Sarkar

doi:10.1063/1.5106426

Abstract

The first-principle calculation with many-body effects explore the electronic and optical properties of newly designed ‘graphyne with BP at hexagonal ring’ (labeled as BP-yne). Our calculations show that BP-yne surface is a direct band gap semiconductor having band gap greater than pristine graphyne and this band gap value is sufficient to overcome the endothermic character of water-splitting reaction and further indicates its possible photocatalytic activities. The Raman and IR spectra analysis indicates quite different feature compare to its structural analogous ‘graphyne with 3BN at ring’ which may help to identify it during synthesis. Its optical absorption can be tuned from near-infrared to UV region depending on the polarization of electric field vector. The optical band gap, as well as the strong absorption peak, lies in the near-infrared region (NIR) and this promising trait can be exploited in biomedical arena.

Highlights

The nanoscale two-dimensional (2D) membranes have stimulated intense interest due to their variety of applications in optoelectronics, spintronics, catalysts, sensors, capacitors, solar cells, batteries, and so on
The valence band maxima (VBM) is mainly contributed by bonding pzπ band of carbon and P atom, while antibonding pzπ∗ band attributed by B and C atom mainly contribute to conduction band minima (CBM) (Fig. 2(c–e))
In case of GW+Bethe-Salpeter equation (BSE) calculation, first strong peak is red-shifted compared to GW corrected one (Fig. 4b(ii)) and the band gap becomes 1.523 eV with significant e-h binding energy (0.337 eV), i.e. the strong peak is located in the near-infrared region (NIR), which points toward its possible use in biomedical application including photothermal therapy and low-power NIR laser irradiation,[53] as ideal photothermal agent should exhibit strong absorbance in NIR region, which is a transparency window for biological tissues.[54]

Summary

Introduction

The nanoscale two-dimensional (2D) membranes have stimulated intense interest due to their variety of applications in optoelectronics, spintronics, catalysts, sensors, capacitors, solar cells, batteries, and so on. The DFT-band gap is found to be 0.814 eV which is larger than graphyne,[18] but smaller than BN- yne sheet.[18,19] The VBM is mainly contributed by bonding pzπ band of carbon and P atom, while antibonding pzπ∗ band attributed by B and C atom mainly contribute to CBM (Fig. 2(c–e)).

Results

Conclusion