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| Type |
Symposium |
| Area |
Physical Chemistry of Materials |
| Room No. |
304호 |
| Time |
THU 14:20-: |
| Code |
PHYS1-3 |
| Subject |
The photophysical mechanisms for the upconversion in lanthanide-doped upconverting nanoparticles (UCNPs) |
| Authors |
이강택
GIST 물리화학부 화학과, Korea |
| Abstract |
Lanthanide-doped upconverting nanoparticles (UCNPs, NaYF4:Yb3+,Er3+) are well known for emitting visible photons upon absorption of two or more near-infrared (NIR) photons through energy transfer from the sensitizer (Yb3+) to the activator (Er3+). Of the visible emission bands (two green and one red band), it has been suggested that the red emission results from two competing upconversion pathways where the non-radiative relaxation occurs after the second energy transfer (pathway A) or between the first and the second energy transfer (pathway B). However, there has been no clear evidence and thorough analysis on the partitioning between the two pathways. In particular, the photophysical pathways of the red emission have been controversial. We examined the spectra, the power dependence of UCNP emission by either 980-nm or 488-nm excitation, to address which pathway is preferred. In addition, we performed stimulated emission depletion measurements, of which the result indicates consistently that the pathway B is the predominant path for the red emission. |
| E-mail |
ktlee@gist.ac.kr |
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119th General Meeting of the KCS