| 초록 |
The charge excitation and decay pathways of two-dimensional heteroatomic quantum dots (QDs) are affected because of quantum confinement effects, bandgap structures and strong exciton binding energies. For this reason, although semiconductor transition metal dichalcogenides (TMDs) have been intensively studied recently, the charge dynamics of metal-phase QDs (mQDs) of TMDs have not been studied relatively. The purpose of this study is to study two sizes of TMD-mQDs with photophysical properties. Here, it occurs because of the different charge excitation and decay pathways, mainly due to defect states and valence band splitting of the TMD-mQDs, resulting in two excitation bands and large stock shifts for maximal photoluminescence. Interestingly, the redshifted dominant excitation band increases with size, and at the excitation wavelength of 266 nm in smaller QDs, the time-resolved PL peak is redshifted and also the lifetime is shortened with larger QDs. In conclusion, from structural and theoretical analyzes, we discuss that the charge decay pathways of smaller QDs are mainly influenced by edge oxidation, whereas vacancies play an important role in larger QDs. |
