Green stimulated emission boosted by nonradiative resonant energy transfer from blue quantum dots

Date
2016
Advisor
Instructor
Source Title
Journal of Physical Chemistry Letters
Print ISSN
1948-7185
Electronic ISSN
Publisher
American Chemical Society
Volume
7
Issue
14
Pages
2772 - 2778
Language
English
Type
Article
Journal Title
Journal ISSN
Volume Title
Abstract

Thanks to their tunability and versatility, the colloidal quantum dots (CQDs) made of II-VI semiconductor compound offer the potential to bridge the "green gap" in conventional semiconductors. However, when the CQDs are pumped to much higher initial excitonic states compared to their bandgap, multiexciton interaction is enhanced, leading to a much higher stimulated emission threshold. Here, to circumvent this drawback, for the first time, we show a fully colloidal gain in green enabled by a partially indirect pumping approach assisted by Förster resonance energy transfer process. By introducing the blue CQDs as exciton donors, the lasing threshold of the green CQDs, is reduced dramatically. The blue CQDs thus serve as an energy-transferring buffer medium to reduce excitation energy from pumping photons in a controlled way by injecting photoinduced excitons into green CQDs. Our newly developed colloidal pumping scheme could enable efficient CQD lasers of full visible colors by a single pump source and cascaded exciton transfer. This would potentially pave the way for an efficient multicolor laser for lighting and display applications.

Course
Other identifiers
Book Title
Keywords
Energy transfer, Excitons, Nanocrystals, Pumping (laser), Semiconductor lasers, Stimulated emission, Colloidal quantum dots, Display application, Exciton transfer, Lasing threshold, Pumping schemes, Resonance energy transfer, Resonant energy transfer, Semiconductor compounds, Semiconductor quantum dots
Citation
Published Version (Please cite this version)