1. Crafting Core/Graded Shell-Shell Quantum Dots with Suppressed Re-absorption and Tunable Stokes Shift as High Optical Gain Materials.
- Author
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Jung, Jaehan, Lin, Chun Hao, Yoon, Young Jun, Malak, Sidney T., Zhai, Yaxin, Thomas, Edwin L., Vardeny, Valy, Tsukruk, Vladimir V., and Lin, Zhiqun
- Subjects
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QUANTUM dots , *ENERGY levels (Quantum mechanics) , *STOKES equations , *CADMIUM analysis , *LIGHT emitting diodes - Abstract
The key to utilizing quantum dots (QDs) as lasing media is to effectively reduce non-radiative processes, such as Auger recombination and surface trapping. A robust strategy to craft a set of CdSe/Cd1− xZn xSe1− yS y/ZnS core/graded shell-shell QDs with suppressed re-absorption, reduced Auger recombination rate, and tunable Stokes shift is presented. In sharp contrast to conventional CdSe/ZnS QDs, which have a large energy level mismatch between CdSe and ZnS and thus show strong re-absorption and a constrained Stokes shift, the as-synthesized CdSe/Cd1− xZn xSe1− yS y/ZnS QDs exhibited the suppressed re-absorption of CdSe core and tunable Stokes shift as a direct consequence of the delocalization of the electron wavefunction over the entire QD. Such Stokes shift-engineered QDs with suppressed re-absorption may represent an important class of building blocks for use in lasers, light emitting diodes, solar concentrators, and parity-time symmetry materials and devices. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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