| 초록 |
Core/shell heterostructure has been utilized to control the optical properties of quantum dots (QDs) for high photoluminescence quantum yield (PL QY) and photochemical stability. Particularly, thick-shell allows to achieve the QDs with suppressed blinking and reduced energy transfer between neighboring QDs. However, the use of thick-shell QDs in applications has been limited due to the low PL QY (≤ 60%) at room temperature. The PL QY loss in thick-shell QDs are attributed to the formation of defects because of the increased strain between two different lattices in core/shell QDs. Applying the alloyed layer at the core/shell interface helps alleviate the structural stress and enhance the optical properties of QDs. Despite these efforts, the PL QY of core/thick-shell QDs have never been surpassed 60%. We demonstrate novel heterostructured QDs with CdS/CdSe/CdS seed/spherical quantum well/shell (SQW) geometry that exhibit near-unity PL QY at room temperature and suppression of blinking. |
