Detailed Observation of Multiphoton Emission Enhancement from a Single Colloidal Quantum Dot Using a Silver-Coated AFM Tip
| Autor: | Hiroki Takata, Sadahiro Masuo, Hideki Fujiwara, Li Wang, Naoto Tamai, Keiji Sasaki, Hiroyuki Naiki |
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| Rok vydání: | 2016 |
| Předmět: |
Chemistry
Mechanical Engineering Physics::Optics Resonance Bioengineering 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Emission intensity Molecular physics 0104 chemical sciences Wavelength Nanocrystal Quantum dot Physics::Atomic and Molecular Clusters General Materials Science Atomic physics 0210 nano-technology Plasmon Excitation Localized surface plasmon |
| Zdroj: | Nano Letters. 16:5770-5778 |
| ISSN: | 1530-6992 1530-6984 |
| DOI: | 10.1021/acs.nanolett.6b02479 |
| Popis: | The enhancement of multiphoton emission from a single colloidal nanocrystal quantum dot (NQD) interacting with a plasmonic nanostructure was investigated using a silver-coated atomic force microscopy tip (AgTip) as the plasmonic nanostructure. Using the AgTip, which exhibited a well-defined localized surface plasmon (LSP) resonance band, we controlled the spectral overlap and the distance between the single NQD and the AgTip. The emission behavior of the single NQD when approaching the AgTip at the nanometer scale was measured using off-resonance (405 nm) and resonance (465 nm) excitation of the LSP. We directly observed the conversion of the single-photon emission from a single NQD to multiphoton emission with reduction of the emission lifetime at both excitation wavelengths as the NQD-AgTip distance decreased, whereas a decrease and increase in the emission intensity were observed at 405 and 465 nm excitation, respectively. By combining theoretical analysis and the numerical simulation of the AgTip, we deduced that the enhancement of the multiphoton emission was caused by the quenching of the single-exciton state due to the energy transfer from the NQD to the AgTip and that the emission intensity was increased by enhancement of the excitation rate due to the electric field of the LSP on the AgTip. These results provide evidence that the photon statistics and the photon flux from the single NQD can be manipulated by the plasmonic nanostructure through control of the spectral overlap and the distance. |
| Databáze: | OpenAIRE |
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