Unraveling the dual emission of single quantum-dot by single particle spectroscopy

Two-color emissive 0D–2D quantum-dot quantum-well (QD-QW) heteronanocrystals has created profound research activities. First multicolor emission in the visible region been reported by Peng and co-workers CdSe(core)–ZnS(barrier)-CdSe(shell) (core-barrier-shell) based heteronanostructures where both CdSe phases (core shell) are tuneable as well. Owing to this enhanced functionality, QD-QW systems colloidal nanocrystals fuelled their optical imaging applications. Single particle spectroscopy taken a giant step toward unravelling features of individual particles thus provide direct information on heterogeneity. To elucidate dual characteristic we performed energy mapped photoluminescence imaging. Surprisingly, pseudo color PL intensity image shows that not all single nature, few either green emitting or red emitting. Photoluminescence spectrum further confirms can be nature. However, dots also present indicating ensemble heterogeneity at levels. The temporal evolution spectra quantum spectral diffusion. dot experiments system unravels hidden photophysics which otherwise observed spectroscopy.