Pore size dependence of self-assembled type photonic crystal on dye-sensitized solar cells efficiency utilising Chlorine e6

Abstract

There are few reports on photoelectric conversion efficiency using naturally-occurring dyes for dyesensitized solar cells (DSSC). This is because the matching with an excited electronic level of naturally-occurring dye to the conduction band of semiconductor is problematic; the excited electrons are easily relaxed to the steady state with fluorescence or heat emission. We examined the fluorescence inhibition effect of a self-assembled photonic crystal using Chlorine e6 dye. Chlorine e6 is derived from chlorophyll and has a long excited electron lifetime. We prepared TiO 2 inverse opals with various particle sizes by liquid phase deposition and described their effect on DSSCs with regard to structural, optical and electrochemical properties. In addition, we explored the implications of fluorescence lifetime measurements relative to the photonic band diagram and the amount of adsorbed dye. Although the main factor affecting the external photoelectric conversion efficiency was the diffusion resistance of the electrolyte and the contact resistance between TiO 2 interfaces, the possibility that the dye fluorescence lifetime, i.e. the photonic band structure, can affect the internal quantum efficiency per one dye molecule was also investigated.

TiO₂ Periodic Structures Fabricated via Top-down and Bottom-up Approaches with a Viewpoint of Photonic Crystal

“…3j. 25 Obviously, the large resistances of our system indicated that the electrolyte intrusion into the inverse opals were not enough.…”

“…could be fabricated using LPD method on polystyrene colloidal crystals. 25 Here the author should mention that these inverse opals can show anomalous group velocity but no complete photonic bandgap.…”

“…The fabricated TiO 2 inverse opals were processed into a dye-sensitized solar cells, and the electrochemical impedance was analysed. 25 …”

Photonic crystals for sensitized solar cells: fabrication, properties, and applications

“…[102,103] A lower Warburg impedance of the gel electrolyte also contributes to the PCE enhancement of an IO PC coupled device. [102] This study offers new strategy and new insight to the coupling of PC to a solar cell for light management. rise to higher fill factor (FF) and PEC than those of smaller pores with larger surface area, which showed the difference, as described above, between QDSSCs and DSSCs.…”

“…It was proposed that the optimized PC structure should has its stop band matched with the absorption peak of the dye. 41 Modified TiO 2 IO structures, including TiO 2 quasi-IO 60 and mesoporous IO PC films, 102 were also fabricated to improve the scattering effect and the surface area of the PC films. By coupling the TiO 2 quasi-IO layer, the PCE was increased from 3.0% to 5.7% for an B4.1 mm thick TiO 2 NP layer and from 4.0% to 6.1% for an B10 mm thick TiO 2 NP layer.…”