Color centers in wide bandgap semiconductors are attracting broad attention for use as platforms for quantum technologies relying on room-temperature single-photon emission (SPE), and for nanoscale metrology applications building on the centers' response to electric and magnetic fields. Here, we demonstrate room-temperature SPE from defects in cubic boron nitride (cBN) nanocrystals, which we unambiguously assign to the cubic phase using spectrally resolved Raman imaging. These isolated spots show photoluminescence (PL) spectra with zero-phonon lines (ZPLs) within the visible region (496-700 nm) when subject to sub-bandgap laser excitation. Second-order autocorrelation of the emitted photons reveals antibunching with g2(0) 0.2,and a decay constant of 2.75 ns that is further confirmed through fluorescence lifetime measurements. The results presented herein prove the existence of optically addressable isolated quantum emitters originating from defects in cBN, making this material an interesting platform for opto-electronic devices and quantum applications.
Bibliographical noteFunding Information:
National Science Foundation (1726573, 1906096, HRD-1547830); Research Corporation (FRED Award). V.M.M. and C.A.M. acknowledge support from the National Science Foundation through grants NSF-1906096 and NSF-1726573. C.A.M. also acknowledges support from Research Corporation for Science Advancement through a FRED Award; all authors acknowledge partial funding and access to the facilities of the NSF CREST IDEALS, grant number NSF-HRD-1547830. VM acknowledges useful discussions with Prof. Igor Aharonovich.
© 2020 Optical Society of America.