Stochastic Photon Emission from Nonblinking Upconversion Nanoparticles
| Autor: | Hohjai Lee, Kyujin Shin, Gibok Lee, Minhyuk Jung, Kang Taek Lee, Youngeun Han, Eunsang Lee |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
business.industry Nanotechnology 02 engineering and technology Nanosecond 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Photon upconversion 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Nanomaterials Ion Upconversion nanoparticles Microsecond General Energy Photon emission Temporal resolution Optoelectronics Physical and Theoretical Chemistry 0210 nano-technology business |
| Zdroj: | The Journal of Physical Chemistry C. 121:21073-21079 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/acs.jpcc.7b08509 |
| Popis: | Because of their well-known optical properties, upconversion nanoparticles (UCNPs) are regarded as some of the most promising nanomaterials for bioimaging, biosensors, and solar cells. The nonblinking nature of their upconversion emissions has been a particularly beneficial advantage for live-cell imaging. However, the origin of this unique property has never been seriously investigated. We report, for the first time, the observation of stochastic photon emission (SPEM) in core/shell UCNPs (NaYF4:Yb3+,Er3+/NaYF4) on the microsecond and nanosecond time scales, even under continuous irradiation at 980 nm. This SPEM was attributed to slow “upconversion cycles”. We consider that the conventionally reported, nonblinking nature of UCNP emissions can be attributed to the averaging of SPEMs from multiple Er3+ ions and the low temporal resolution of previous observation. The off-time distribution, which possesses kinetics information for the upconversion pathways, was well fitted to a single exponential indicating... |
| Databáze: | OpenAIRE |
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