Sequential “click” functionalization of mesoporous titania for energy-relay dye enhanced dye-sensitized solar cells

Abstract

Energy relay dyes (ERDs) have been investigated previously as a mean to achieve panchromatic spectral response in dye-sensitized solar cells via energy transfer. To reduced the distance between the ERDs and energy-accepting injection dyes (IDs) on the surface of a mesoporous titanium dioxide electrode, the ERDs were immobilized adjacent to the IDs via a sequential functionalization approach. In the first step, azidobenzoic acid molecules were co-adsorbed on the mesoporous titanium dioxide surface with the ID. In the second step, the highly selective copper(I)-catalyzed 1,3-dipolar azide-alkyne cycloaddition "click" reaction was employed to couple an alkyne-functionalized ERD to the azidobenzoic acid monolayer. The cycloaddition step in the mesoporous electrode was slowed dramatically due to reactants and catalysts forming agglomerates. In solar cell devices, the close proximity between the surface-immobilized ERD and energy-accepting squaraine sensitizer dyes results in energy transfer efficiencies of up to 91%. The relative improvement in device performance due to the additional ERD spectral response was 124%, which is among the highest reported. The sequential functionalization approach described herein is transferrable to other applications requiring the functionalization of electrodes with complex molecules.

Electron Injection and Energy-Transfer Properties of Spiropyran–Cyclodextrin Complexes Coated onto Metal Oxide Nanoparticles: Toward Photochromic Light Harvesting

“…It has been shown that DSSCs can be constructed with visible-light absorbing energy relay dyes that undergo FRET to near-IR dye-sensitized electrodes. ,− The purpose of the energy relay dye, either doped in the electrolyte or linked to the surface or dye sensitizer, is to funnel its absorbed energy to the dye sensitizer, which is the primary electron-injecting component. We have demonstrated a high Φ FRET is achieved between MC-CDs and squaraine dye sensitizers on a zirconia surface.…”

Investigation and Optimization of Mxene Functionalized Mesoporous Titania Films as Efficient Photoelectrodes

“…Generally, increased charge kinetics are desirable at the thin pore walls and shorter mesochannels [ 20 ]. Nevertheless, the conductance of photoinduced electrons within the oxide framework is supported by the diffusion process, and is predominantly affected by the charge trapping and detrapping states due to the crystallographic defects which occur within single particles and at the contact peripheries among neighboring species [ 21 ].…”

The influence of yttrium dopant on the properties of anatase nanoparticles and the performance of dye-sensitized solar cells

“…2 Among various candidates, TiO 2 has been identified as a promising photoanode material and has been widely investigated. [3][4][5] Generally, to effectively adsorb dyes, a large specific surface area (SSA) is necessary; 6 therefore, various technologies have been developed to enlarge the SSA, such as micelles, 7,8 block copolymers 9 and ordered templates. 10 Unfortunately, all those approaches need post-processing, 11,12 which retard their application.…”