Samsung Advanced Institute of Technology

We prepared isotropic InP/ZnSe/ZnS quantum dots (QDs) at high reaction temperature, which facilitated ZnSe shell growth on random facets of the InP core. Fast crystal growth enabled to eliminate stacking faults, which induced anisotropic growth, and as a result, to improve the photoluminescence (PL) quantum yield by nearly 20％. We also investigated the effect of the QD morphology on photophysical properties by observing the PL blinking dynamics and ultrafast hole relaxation rates. It was found that hot hole trapping was considerably suppressed in isotropic InP QDs, indicating that the stacking faults in the anisotropic InP/ZnSe structures acted as defects for luminescence. These results highlight the importance of understanding the correlation between QD shapes and hot carrier dynamics, and present a way to design highly luminescent QDs for further promising display applications.