Supplementary Information for
Ligand-Dependent Luminescence of
ultra-small Eu3+ -doped NaYF4 nanoparticles
Dominika Wawrzynczyk1, Artur Bednarkiewicz2,3*, Marcin Nyk1, Wiesław Strek2 and
Marek Samoc1,*
1
Institute of Physical and Theoretical Chemistry, Wroclaw University of Technology,
Wyb. Wyspianskiego 27, 50370 Wroclaw, Poland
2
Institute of Low Temperature and Structure Research, Polish Academy of Science,
Okolna 2, 50422 Wroclaw, Poland
3
Wroclaw Research Center, EIT+, Stablowicka 147, 54-066 Wroclaw, Poland
* To whom correspondence should be addressed:
marek.samoc@pwr.wroc.pl,
tel: + 48 71 320-44-66,
fax: + 48 71 320-33-64,
Wroclaw University of Technology,
Institute of Physical and Theoretical Chemistry,
Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland
a.bednarkiewicz@int.pan.wroc.pl
tel: + 48 71 395-41-66
Department of Spectroscopy of Excited States
Institute of Low Temperature and Structure Research
Polish Academy of Sciences
ul. Okolna 2, 50-422 Wroclaw, Poland
-1
2921 cm
2851 cm
-1
OA
OANPs
-1
a)
1467 cm
-1
1562 cm
Absorbance
Figure 1S. FTIR spectra of the synthesized OANPs (a), TOPONPs (b) and HDANPs (c),
together with corresponding FTIR spectra for the ligands used during synthesis protocols.
2921 cm
-1
2851 cm
2921 cm
1570 cm
-1
1670 cm
-1
HDA
HDANPs
2851 cm
-1
c)
-1
-1
1450 cm
-1
1467 cm
TOPO
TOPONPs
-1
b)
500
1000 1500 2000 2500 3000
-1
Wavenumber [cm ]
In the three synthesized NaYF4:4%Eu3+ samples intense IR peaks at 2921cm-1 and 2851cm-1
were assigned to the asymmetric (Vas) and symmetric (Vs), respectively, stretching vibrations
of methylene groups (CH2) in the long alkyl chain present in the organic molecules used as
capping ligands (Chen et al. 2008). In addition, for OANPs, bands at 1562 cm-1 and 1467 cm-1
were found in the spectrum, associated with the asymmetric (Vas) and symmetric (Vs)
stretching vibrations of the carboxylic group of the bound oleic acid (Chen et al. 2008). For
TOPONPs the presence of a strong IR peak at 1467 cm−1 with a shoulder at ∼1450cm−1
corresponds to P=O stretching vibrational modes indicating the signatures of the capping
TOPO agent(Becerra et al. 1994; Sharma et al. 2008). For HDANPs, bands at 1570 cm−1 and
at 1670 cm−1 correspond to N-H bending vibrational modes indicating also the presence of the
HDA capping agent on NPs surface(Coates 2000).
Table.1S. Asymmetry ratios for NaYF4:4%Eu3+ NPs with different surface ligands dispersed
in chloroform, toluene, THF and cyclohexane.
Asymmetry
ratio R
NaYF4:4%Eu3+
OANPs
TOPONPs
HDANPs
in CHCl3
1.30
in Toluene
1.27
in THF
1.29
in Cyclohexane
1.29
in CHCl3
2.96
in Toluene
2.78
in THF
-
in Cyclohexane
2.92
in CHCl3
1.09
in Toluene
1.11
in THF
1.16
in Cyclohexane
1.12
Table 2S. Luminescence lifetimes of the 5D0 excited state in Eu3+ ions embedded in NaYF4
matrix with different surface ligands dispersed in chloroform, toluene, THF and cyclohexane,
and corresponding values for NPs after ligand removal and dispersing them in water.
5
NaYF4:4%Eu3+
D0 excited state
luminescence
lifetime 1[s]
5
D0 excited state
luminescence
lifetime 2 [s]
in CHCl3
0.00234± 4.3x10-5
0.00699 ± 1.1x10-4
in Toluene
0.00245± 1.5x10-5
0.00743 ± 3.3x10-5
in THF
0.00289± 1.4x10-5
0.00787 ± 4.9x10-5
in Cyclohexane
0.00210± 1.3x10-5
0.0065 ± 3.0x10-5
in CHCl3
0.00149± 1.1x10-5
0.00365 ± 1.5x10-5
in Toluene
0.00147± 9.3x10-6
0.0035 ± 1.6x10-5
in THF
-
-
in Cyclohexane
0.00117± 9.4x10-6
0.00337 ± 1.3x10-5
in CHCl3
0.0121± 0.00133
0.00596 ± 1.1x10-4
in Toluene
0.00909± 8.7x10-4
0.0051 ± 1.9x10-4
in THF
0.00956± 3.3x10-4
0.00451 ± 1.2x10-4
in Cyclohexane
0.01138± 8.1x10-4
0.00577 ± 9.9x10-5
OANPs
in water
-
0.000134 ± 6.6x10-6
TOPONPs
in water
-
0.00011 ± 4.4x10-7
HDANPs
in water
-
0.00011 ± 1.3x10-6
OANPs
Ligand free in air
-
0.000118 ± 1.8x10-6
TOPONPs
Ligand free in air
-
0.000117 ± 3.5x10-7
HDANPs
Ligand free in air
-
0.000114 ± 3.3x10-6
OANPs
TOPONPs
HDANPs
Luminescence lifetime 1 [s]
Figure 2S. Dependence of the short component of 5D0 excited state lifetimes of Eu3+ ions
embedded in NaYF4 matrix with OA (blue squares), TOPO (red) and HDA (black) ligands
present on the surface, on the refractive index of the solvent.
1.4x10
-2
1.3x10
-2
1.2x10
-2
1.1x10
-2
1.0x10
-2
9.0x10
-3
8.0x10
-3
7.0x10
-3
6.0x10
-3
5.0x10
-3
4.0x10
-3
3.0x10
-3
2.0x10
-3
1.0x10
-3
HDANPs
TOPONPs
OANPs
Cyclohexane
Toluene
THF
Chloroform
1.40 1.41 1.42 1.43 1.44 1.45 1.46 1.47 1.48 1.49 1.50 1.51
nsolvent
Figure 3S. Dependence of the long component of 5D0 excited state lifetimes of Eu3+ ions
embedded in NaYF4 matrix with OA (blue squares), TOPO (red) and HDA (black) ligands
present on the surface, on the refractive index of the solvent.
HDANPs
TOPONPs
OANPs
Luminescence lifetime [s]
-3
9.0x10
-3
8.5x10
THF
-3
8.0x10
Toluene
-3
7.5x10
Chloroform
-3
7.0x10
Cyclohexane
-3
6.5x10
-3
6.0x10
-3
5.5x10
-3
5.0x10
-3
4.5x10
-3
4.0x10
-3
3.5x10
-3
3.0x10
1.40
1.41
1.42
1.43
1.44
1.45
1.46
nsolvent
1.47
1.48
1.49
1.50
1.51
Figure 4S. Luminescence lifetimes short component of the 5D0 excited state in Eu3+ ions
embedded in NaYF4 matrix with different capping surface ligands vs. ligand refractive index.
Luminescence lifetime 1 [s]
-2
1.4x10
-2
OANPs
1.3x10
-2
1.2x10
-2
1.1x10
-2
1.0x10
-3
9.0x10
-3
8.0x10
-3
7.0x10
-3
6.0x10
-3
5.0x10
-3
4.0x10
HDANPs
-3
3.0x10
TOPONPs
-3
2.0x10
-3
1.0x10
Ligand free NPs in water
0.0
1.30
1.32
1.34
1.36
1.38
1.40
1.42
1.44
1.46
1.48
nligand
Figure 5S. Luminescence lifetimes long component of the 5D0 excited state in Eu3+ ions
embedded in NaYF4 matrix with different capping surface ligands vs. ligand refractive index.
Luminescence lifetime [s]
-3
7.5x10
-3
OANPs
7.0x10
-3
6.5x10
-3
6.0x10
HDANPs
-3
5.5x10
-3
5.0x10
-3
4.5x10
-3
4.0x10
TOPONPs
-3
3.5x10
-3
3.0x10
-3
2.5x10
-3
2.0x10
-3
1.5x10
-3
1.0x10
-4
5.0x10
0.0
1.30
Ligand free NPs in water
1.32
1.34
1.36
1.38
1.40
nligand
1.42
1.44
1.46
1.48
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