Optical spectroscopy of single colloidal CsPbBr3 perovskite nanoplatelets.

Optically bright lead halide perovskite nanocrystals of different morphologies ranging from nanocubes to flat nanoplatelets to elongated nanowires have been reported. The morphology of the nanocrystals is expected to affect various properties such as the band edge energy and the electron-hole exchange interaction. However, aside from nanocubes, the investigation of the optical properties of the lead halide perovskite nanocrystals of different morphologies at the single emitter level has been lacking. We have performed optical spectroscopy in single CsPbBr3 nanoplatelets and observed a single photon emission without blinking. Furthermore, the PL emission exhibits excitonic fine structure peaks similar to what has been previously observed in nanocubes. Our work paves the way for further investigations into the excitonic and quantum optics properties when the lateral size and morphology can be further controlled in lead halide perovskite nanocrystals.