Figure 1.
The schematic of the basic DSC design, also showing the chemically linked AuNPs plasmonic enhancement layer used herein on top of TiO2 particles.
Figure 2.
SEM image subsequent to focused ion beam milling to evaluate the absolute thickness of the TiO2 layer; magnification 3500x and scale bar 10 µm (A).
SEM confirming the TiO2 average thickness of 7.45 µm, magnification 12500x and scale bar 5 µm (B).
Figure 3.
SEM image of the AuNPs immobilized on Si (A); SEM image showing the AuNPs dispersed on Si wafer (B); SEM image of a single AuNP; magnification 150,000x and scale bar 300 nm (C).
Figure 4.
SEM image of the TiO2 nanoparticles (Ø ∼20 nm), with optically dispersing TiO2 particles (Ø ∼190 nm) and functionalized with AuNPs; magnification 50,000x and scale bar 500 nm.
Figure 5.
The XPS analysis confirming the TiO2-S and the S-AuNPs bonding.
(A) The survey; (B) The effects of the AuNPs functionalization on the TiO2 (shifts of the Ti 2p peaks); (C) Confirmation of the AuNPs presence (Au 4f) and the peak fitting; (D) The XPS peak fitting of Ti 2p for pure TiO2 samples; (E) The XPS peak fitting of Ti 2p for samples with TiO2 and dithiodibutyric acid linker; (F) The XPS peak fitting of Ti 2p for samples with AuNPs attached to the TiO2 via the linker.
Figure 6.
Raman spectra of TiO2 samples with Ru N749, and of TiO2 samples with AuNPs plus Ru N749.
Table 1.
Raman modes and their assignment to either TiO2 or Ru N749.
Figure 7.
The absorbance as a function of wavelength for Ru N719 without AuNPs and the simulated AuNPs extinction (A); Measured and simulated absorbance enhancement of Ru N719 DSCs when using tailored AuNPs (B).
Figure 8.
Comparison of the J-V curves of DSCs based on N719, N749, N3 and DSCs based on dyes plus AuNPs (N719NPs, N749NPs, N3NPs).
Table 2.
DSC performance parameters, showing the overall increase (in %) achieved herein predominantly for the JSC, when using the proposed experimental approach of plasmonic enhancement.