title: Green Stimulated Emission Boosted by Nonradiative Resonant Energy Transfer from Blue Quantum Dots.
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.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, 637371, Singapore.|LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering and The Photonics Institute, Nanyang Technological University , 50 Nanyang Avenue, 639798, Singapore.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, 637371, Singapore.
authors.forename: Guannan
authors.initials: G
authors.lastname: Yu
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, 637371, Singapore.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.affiliation: LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering and The Photonics Institute, Nanyang Technological University , 50 Nanyang Avenue, 639798, Singapore.
authors.forename: Cuong
authors.initials: C
authors.lastname: Dang
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, 637371, Singapore.
authors.forename: Tze Chien
authors.initials: TC
authors.lastname: Sum
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, 637371, Singapore.|LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering and The Photonics Institute, Nanyang Technological University , 50 Nanyang Avenue, 639798, Singapore.
authors.forename: Handong
authors.initials: H
authors.lastname: Sun
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, 637371, Singapore.|LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering and The Photonics Institute, Nanyang Technological University , 50 Nanyang Avenue, 639798, Singapore.|Department of Electrical and Electronics Engineering and Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University , 06800 Bilkent, Ankara, Turkey.
authors.forename: Hilmi Volkan
authors.initials: HV
authors.lastname: Demir