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Defect‐Based Modulation of Optoelectronic Properties for Biofunctionalized Hexagonal Boron Nitride Nanosheets
Author(s) -
ShakourianFard Mehdi,
Heydari Hadiseh,
Kamath Ganesh
Publication year - 2017
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201700512
Subject(s) - nucleobase , binding energy , boron , homo/lumo , blueshift , band gap , boron nitride , biosensor , materials science , crystallography , chemistry , photochemistry , dna , nanotechnology , optoelectronics , molecule , photoluminescence , atomic physics , organic chemistry , biochemistry , physics
Defect engineering potentially allows for dramatic tuning of the optoelectronic properties of two‐dimensional materials. With the help of DFT calculations, a systematic study of DNA nucleobases adsorbed on hexagonal boron‐nitride nanoflakes (h‐BNNFs) with boron (V B ) and nitrogen (V N ) monovacancies is presented. The presence of V N and V B defects increases the binding strength of nucleobases by 9 and 34 kcal mol −1 , respectively (h‐BNNF‐V B >h‐BNNF‐V N >h‐BNNF). A more negative electrostatic potential at the V B site makes the h‐BNNF‐V B surface more reactive than that of h‐BNNF‐V N , enabling H‐bonding interactions with nucleobases. This binding energy difference affects the recovery time—a significant factor for developing DNA biosensors—of the surfaces in the order h‐BNNF‐V B >h‐BNNF‐V N >h‐BNNF. The presence of V B and V N defect sites increases the electrical conductivity of the h‐BNNF surface, V N defects being more favorable than V B sites. The blueshift of absorption peaks of the h‐BNNF‐V B –nucleobase complexes, in contrast to the redshift observed for h‐BNNF‐V N –nucleobase complexes, is attributed to their observed differences in binding energies, the HOMO–LUMO energy gap and other optoelectronic properties. Time‐dependent DFT calculations reveal that the monovacant boron‐nitride‐sheet–nucleobase composites absorb visible light in the range 300–800 nm, thus making them suitable for light‐emitting devices and sensing nucleobases in the visible region.