Accidental Contamination of Substrates and Polymer Films by Organic Quantum Emitters

Abstract

We report the observation of ubiquitous contamination of dielectric substrates and poly(methyl methacrylate) matrices by organic molecules with optical transitions in the visible spectral range. Contamination sites of individual solvent-related fluorophores in thin films of poly(methyl methacrylate) constitute fluorescence hotspots with quantum emission statistics and quantum yields approaching 30% at cryogenic temperatures. Our findings not only resolve prevalent puzzles in the assignment of spectral features to various nanoemitters on bare dielectric substrates or in polymer matrices but also identify the means for the simple and cost-efficient realization of single-photon sources in the visible spectral range.

Room-temperature single-photon emitters in silicon nitride

“…This value is clearly lower than the separation of the emission lines of SPEs in silica. Besides the spectral differences compared with our SiN SPEs, these three-peak spectra with a zero-phonon line and phonon sidebands are similar to those recently attributed to accidental contamination of dielectric substrates or polymer matrices with organic molecules ( 48 ). Note that we measured the optical properties of bare SiO 2 (3 μm)–on–Si wafers used for SiN deposition.…”

Quantum Emitter Localization in Layer-Engineered Hexagonal Boron Nitride

“…Such polymer residues are known to give rise to localized emission within the same spectral range, 570 to 620 nm, as the various hBN lattice defects. 43,54,55 Using a "dummy" transfer without hBN (see Experimental Methods), we estimate the emission site density attributable to PVA residuals and other background/ adsorbates to be ∼0.007 emission sites/μm 2 (see SI, Figure S4a), that is, constituting about 17% of the overall emission site density of the as-transferred hBN film (Figure 2a, green band).…”

DNA‐Mediated Self‐Assembly of Plasmonic Antennas with a Single Quantum Dot in the Hot Spot

“…This procedure established a spatial correlation between spots exhibiting fluorescence and the scattering signals of the antennas. The matching of fluorescence and DF measurements allows the selective analysis of only those emission spots corresponding to the targeted structures while discarding any potential fluorescent contaminants . From the series of frames obtained in the epifluorescence measurements, we extracted an intensity time trace for each fluorescent spot (Note S5, Supporting Information).…”