Abstract
We demonstrate that the geometries of the absorption dipole 1/4ab and emission dipole 1/4em of nano-emitters such as quantum dots can be determined simultaneously by far-field polarimetry. The method involves plotting the emission polarization ratio against the absorption polarization ratio of single nano-emitters. Using Monte Carlo simulation, we show that these plots depend sensitively on the aspect ratio of the dipole shape. For example, the so-called 3D-2D dipole combination, that is, 1/4ab of radius ratio 1:1:1 and 1/4em of ratio 1:1:0, would give rise to a vertical line plot. Polarization ratios of commercial cadmium selenide/zinc sulfide (CdSe/ZnS) quantum dots are measured and plotted. The empirical data points are best-fitted to yield 1/4ab of radius ratio 1:1:0.28 and 1/4em of ratio 1:1:0.
Original language | English |
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Pages (from-to) | 302-311 |
Number of pages | 10 |
Journal | Applied Spectroscopy |
Volume | 70 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 Feb 2016 |
User-Defined Keywords
- Dipole geometry
- polarimetry
- quantum dots