| 초록 |
Colloidal quantum dots (QDs) can have high quantum efficiency, tunable color, and narrow spectral linewidth, making them suitable for light sources. In the recent study, QDs with high efficiency with a color range from purple to cyan were synthesized using ZnSe1-XTeX alloys. However, as the ratio of Te was increased to adjust the color toward blue regions, a sudden increase in linewidth occurred in all previous reports. The lack of understanding of its origin makes it difficult to fabricate blue ZnSe1-XTeX QDs with narrow linewidth. In this study, temporally and spectrally resolved ensemble measurements and single dot measurements were performed on ZnSe1-XTeX QDs with various Te ratios. Through this, it was possible to analyze inhomogeneous and homogeneous broadening which makes it possible to predict the existence of a new electronic state caused by the Te. And through density functional theory, it was found that a hole trap state can occur when two Te exist adjacent to each other in the crystal structure, and this is the reason of the sudden increase in linewidth. These results may suggest future research directions for making blue light-emitting sources through ZnSe1-XTeX QDs. |
