Solvent Effects on the Blinking Statistics of Color Centers in Chemical Vapor Deposition-Grown hBN.

We investigate how the local solvent environment influences the fluorescent behavior of multiple fluorescent emitters with high likelihood of presence of single photon emitters (SPEs) in chemical-vapor-deposited (CVD) hexagonal boron nitride (hBN). Widefield total internal reflection fluorescence (TIRF) microscopy and hyperspectral confocal imaging were used to quantify emitter activation, emission spectra, and intermittency dynamics in air and after exposure to water, ethanol, isopropanol (IPA), and hexane. The apparent surface density of active emitters increased by factors of 2.1 ± 0.4, 2.5 ± 0.3, and 3.9 ± 0.6 after addition of IPA, water, and ethanol, respectively, while hexane produced a 30 ± 5% decrease. Emission peaks were observed at 529, 582, 600, and 617 nm, each accompanied by a phonon sideband red-shifted by 170 ± 10 meV. Time-trace analysis revealed power-law-distributed bright- and dark-state dwell times ranging from 0.05 s to >100 s. Polar solvents altered the power-law exponents, indicating shorter bright events and longer dark periods relative to air. These results show that solvent polarity and hydrogen-bonding capability significantly modulate emitter activation and blinking behavior in hBN, providing quantitative insight into solvent-defect interactions at the nanoscale.