Dongju Jung1,Hakjune Lee2,Doyoon Shin1,Jaemin Lim1,Seongbin Im1,Jeongwoo Park1,Wan Ki Bae1
Sungkyunkwan university1,Seoul National University2
Dongju Jung1,Hakjune Lee2,Doyoon Shin1,Jaemin Lim1,Seongbin Im1,Jeongwoo Park1,Wan Ki Bae1
Sungkyunkwan university1,Seoul National University2
Colloidal quantum dots (QDs) made of heavy metal free elements can have high quantum efficiency, tunable color, and narrow spectral linewidth, making them suitable for use as light sources. In a recent study, QDs with high luminous efficiency with a color range from purple to blue and cyan were synthesized using ZnSe<sub>1-X</sub>Te<sub>X</sub> alloys. However, as the ratio of Te was increased to adjust the color toward the blue region, a sudden increase in linewidth occurred in all previous reports. The lack of understanding of its origin makes it difficult to fabricate blue ZnSe<sub>1-X</sub>Te<sub>X</sub> QDs with narrow linewidth. In this study, temporally and spectrally resolved ensemble measurements and single dot measurements were performed on ZnSe<sub>1-X</sub>Te<sub>X</sub> 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 state caused by the influence of 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 ZnSe<sub>1-X</sub>Te<sub>X</sub> QDs.