Unraveling sources of emission heterogeneity in Silicon Vacancy color centers with cryo-cathodoluminescence microscopy

• DOI: 10.1073/pnas.2308247121
• Publication Date: 2024-03-29T16:32:00Z
• Authors: Daniel K. Angell; Shuo Li; Hendrik Utzat; Matti L. S. Thurston; Yin Liu; Jeremy Dahl; Robert Carlson; Zhi-Xun Shen; Nicholas Melosh; Robert Sinclair; Jennifer A. Dionne
• Keywords: Cathodoluminescence; Nanodiamond

Diamond color centers have proven to be versatile quantum emitters and exquisite sensors of stress, temperature, electric magnetic fields, biochemical processes. Among centers, the silicon-vacancy (SiV[Formula: see text]) defect exhibits high brightness, minimal phonon coupling, narrow optical linewidths, degrees photon indistinguishability. Yet creation reliable scalable SiV[Formula: text]-based has been hampered by heterogeneous emission, theorized originate from surface imperfections, crystal lattice strain, symmetry, or other impurities. Here, we advance high-resolution cryo-electron microscopy combined with cathodoluminescence spectroscopy 4D scanning transmission electron (STEM) elucidate structural sources heterogeneity in text] emission nanodiamond sub-nanometer-scale resolution. Our diamond nanoparticles are grown directly on TEM membranes molecular-level seedings, representing natural formation conditions diamond. We show that individual subcrystallites within a single exhibit distinct zero-phonon line (ZPL) energies differences brightness can vary 0.1 meV energy over 70% brightness. These changes correlated atomic-scale structure. find ZPL blue-shifts result tensile while red shifts due compressive strain. also crystallites host densities grain boundaries impact significantly. Finally, interrogate nanodiamonds as small 40 nm diameter these diamonds no spatial change their energy. work provides foundation for structure-emission correlation, e.g., atomic defects range two-dimensional materials.