Intrinsic and Surface Defect‐Rich Boron Nitride Quantum Dots With Stable Zero‐Phonon Lines and Phonon Sidebands

ABSTRACT

Boron nitride quantum dots (BNQDs), when excited at 532 nm, emit multiple zero‐phonon lines from 2.10 to 2.20 eV. Raman peaks at 913 due to B‐O or B‐OH vibrations or boron oxide ( or boric acid), 1202 is defect or edge‐induced modes or impurities, 1279 defect or edge‐induced modes or zone‐edge phonons, 1472 and 1648 due to vibrational modes of BNQD were observed. The photoluminescence (PL) spectrum, excited at 262 nm (), showed emission at 370 nm (). The PL spectrum shows a peak at 288 nm (4.3 eV), identified as a zero‐phonon line (ZPL) of defect in hBN, matching that simulated from DFT calculations, or may be attributed to the defect noted in bulk hBN. At all temperatures, tentatively is found around 3.04 to 2.95 eV. Similarly, the luminescent center is tentatively assigned for the emission around 2.7–2.07 eV.