Quantum efficiency of single NV centers in nanodiamonds

Nitrogen-vacancy (NV) centers in nanodiamond are photostable single photon emitters at room temperature and are considered to be promising candidates for integrated nanophotonics and quantum information processing. A successful implementation of NV centers in nanophotonic devices requires knowledge about the photophysical properties of each emitter such as brightness, decay rate and quantum efficiency. Recent reports show that not all NV centers in diamond nanocrystals are identical and indeed show distributions in brightness and decay rate [1,2]. Here, we report on experimental quantification of the quantum efficiency (QE) of individual nanodiamonds containing single NV centers. Additionally, we report on measurements of decay rate and brightness of single nanodiamond NV centers and discuss if/which NV centers are suitable emitters to be integrated in nanophotonic devices.