1
Plasmonic Enhancement of Dye Sensitized Solar Cells
in the Red-to-NIR Region using Triangular Core-Shell
Ag@SiO2 Nanoparticles
Mahesh K. Gangishetty,† Kee Eun Lee,
† Robert W. J. Scott, and Timothy L. Kelly*
Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK, S7N
5C9, Canada
† These authors contributed equally to this work.
* Address correspondence to: [email protected]
2
Figure S1. TEM images of the as-prepared silver nanoprisms.
Figure S2. Size distributions of the as-prepared silver nanoprisms: (a) edge length, and (b)
thickness.
10 15 20 25 30 35 40 45 50 55 600
10
20
30
40
(a)
Counts
Nanoprism Edge Length (nm)
0 1 2 3 4 50
5
10
15
20
25
30(b)
Counts
Nanoprism Thickness (nm)
3
Figure S3. UV/Vis/NIR spectra of the as-prepared silver nanoprisms (black line) and the
nanoprisms after functionalization with 16-mercaptohexadecanoic acid (red line).
Figure S4. Schematic depiction of the device architecture, showing the Ag@SiO2 nanoparticles
embedded in the TiO2 photoanode.
400 500 600 700 800 900 10000.0
0.2
0.4
0.6
0.8
1.0
Optical Density
Wavelength (nm)
4
Table S1. Analysis of variance (ANOVA) analysis of power conversion efficiency as a function of
Ag@SiO2 loading, carried out at the 95% confidence level. The calculated F-value (13.3) is larger
than the critical F-value (2.3) required for 95% confidence, and the P-value is less than 0.05.
Therefore, the results show a statistically significant variation in PCE with Ag@SiO2 loading.
Anova: Single Factor
SUMMARY
Ag@SiO2 Loading Count Sum Average Variance
0.00% 15 83.1881 5.545873 0.367689
0.01% 4 25.3545 6.338625 0.25448
0.05% 13 95.8342 7.371862 0.465648
0.10% 4 28.4597 7.114925 0.170996
0.33% 6 40.1648 6.694133 0.251301
0.50% 4 27.2061 6.801525 0.087758
1.00% 4 27.0449 6.761225 0.127536
ANOVA
Source of Variation SS df MS F P-value F crit
Between Groups 25.91521 6 4.319202 13.34788 1.78E-08 2.318498
Within Groups 13.91425 43 0.323587
Total 39.82946 49
5
Table S2. Pairwise t-tests (assuming unequal variances, 95% confidence) comparing the power
conversion efficiencies of devices made with various Ag@SiO2 loadings with pure TiO2 controls. In
all cases, the absolute value of the t-statistic is larger than the critical t-value required for 95%
confidence in a two-tailed test, and the P-value is less than 0.05. Therefore, each sample shows a
statistically significant increase in PCE relative to the TiO2 controls.
Ag@SiO2 Loading 0.00% 0.01% 0.00% 0.05% 0.00% 0.10%
Mean 5.546 6.339 5.546 7.372 5.546 7.115
Variance 0.368 0.254 0.368 0.466 0.368 0.171
Observations 15 4 15 13 15 4
Hypothesized Mean Difference 0 0 0
df 6 24 7
t Stat -2.670 -7.434 -6.050
P(T<=t) one-tail 0.019 0.000 0.000
t Critical one-tail 1.943 1.711 1.895
P(T<=t) two-tail 0.0370
1.13E-
07 0.0005
t Critical two-tail 2.447 2.064 2.365
Ag@SiO2 Loading 0.00% 0.33% 0.00% 0.50% 0.00% 1.00%
Mean 5.546 6.694 5.546 6.802 5.546 6.761
Variance 0.368 0.251 0.368 0.088 0.368 0.128
Observations 15 6 15 4 15 4
Hypothesized Mean Difference 0 0 0
df 11 11 8
t Stat -4.456 -5.826 -5.118
P(T<=t) one-tail 0.000 0.000 0.000
t Critical one-tail 1.796 1.796 1.860
P(T<=t) two-tail 0.0010 0.0001 0.0009
t Critical two-tail 2.201 2.201 2.306
6
Figure S5. (a) Incident photon-to-current efficiency spectra of DSSCs made using 0.0% (black line)
and 0.05% (red line) Ag@SiO2 loadings. The difference spectrum is also shown (blue line). (b) The
relative IPCE enhancement ((IPCEAg@SiO2 − IPCEcontrol) / IPCEcontrol) for the device with a 0.05%
Ag@SiO2 loading (blue line) and the original IPCE spectrum (black line).
Figure S6. TEM image of the Ag@SiO2 nanoparticles with the thickest SiO2 shells after sintering.
300 400 500 600 700 800 9000
10
20
30
40
50
60
70
80 0.0% Ag
0.05% Ag
Difference
IPCE (%)
Wavelength (nm)
(a)
300 400 500 600 7000
10
20
30
40
50
60
70
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
IPCE (%)
Wavelength (nm)
(b)∆∆ ∆∆ IPCE / IP
CE
7
Figure S7. Average power conversion efficiency for DSSCs prepared using 0.05% (w/w) of
Ag@SiO2 nanoprisms with different shell thicknesses, as well as for the control devices without any
Ag@SiO2. The thickness of the photoanode in all devices was 3 – 4 µm. The error bars show plus
or minus one standard deviation from the mean.
4
5
6
7
33 nm SiO2
7 nm SiO2
Power Conversion Efficiency (%)
TiO2 Control
8
Table S3. Device performance characteristics for DSSCs prepared using 0.05% (w/w) of Ag@SiO2
nanoprisms with different shell thicknesses, as well as for the control devices without any
Ag@SiO2. The thickness of the photoanode in all devices was 3 – 4 µm.
Device Type Average
VOC (V)
Average JSC
(mA/cm2)
Average FF
(%)
Average
PCE (%)
TiO2 Control 0.63 ± 0.02 9.3 ± 0.8 72.9 ± 0.2 4.3 ± 0.5
7 nm Ag@SiO2 0.68 ± 0.01 9.1 ± 0.6 73.3 ± 0.8 4.6 ± 0.3
33 nm Ag@SiO2 0.65 ± 0.01 12.9 ± 0.9 71.7 ± 0.8 6.1 ± 0.5