Objectives:
The primary objective is to gain a predictable leapfrog of long-term power output of DSC through novel multifunctional nanomaterials and molecular architectures utilizing materials design, development and processing.
This can be split into the following key objectives:
I. Design and synthesis of innovative dye-sensitizers with unprecedented performance, property tunability and stability.
Confer highly efficient and spectrally selective light harvesting and supramolecular hole transport properties to the ruthenium sensitizers by appropriate molecular engineering of their ligands, increasing at the same time their stability grafting onto TiO2. Pursue ligand engineering to ensure a high open circuit potential in DSC. Increase the long-term stability of ruthenium sensitizers by replacing their thiocyanate ligands. Develop organic and metallorganic sensitizers endowed with very high molar extinction coefficients and tunable absorption from the visible into the near-IR regions. Evaluate series of homologous sensitizers in which a continuous variation of the oxidation potential allows to gauge the limiting factors for oxidized dye recombination by the electrolyte. Evaluate possible interactions between the dyes and electrolyte components to minimize recombination.
II. Explore new concepts of photon capture by quantum dots and thin-film inorganic materials.
Evaluate and determine the forecast benefits of quantum dot technology chemically bound to the mesoscopic architecture of the charge collecting oxide semiconductor. The purpose of the quantum dot-based antenna is to provide efficient capture of near IR light and efficient charge extraction, modulated by varying their size and shape. The materials as well as their molecular and mesoscopic architecture will be judiciously selected to yield maximal power generation. Evaluate the potential of extremely thin absorbers (ETA) based on inorganic materials, such as Sb2S3 and Bi2S3 metal-chalcogenides in innovative DSC configurations, including organic hole transporters for solid-state devices.
III. Provide means for enhanced and vectorial electron transport in the mesoscopic semiconductor through chemical control of the nanostructure, with incorporation of nanorod/nanotube morphologies.
IV. Improve the stability over traditionally employed electrolytes by investigating novel transition metal complexes as standalone redox mediators which are inexpensive, transparent and redox stable. Investigate novel redox mediators based on organic redox couples to induce stable and efficient charge separation and regeneration, as alternatives to existing hole-transporting materials, which are coloured (problems with filtering) while starting from existing organic redox couples we may more easily convert them into colourless materials. These novel electrolytes are also better compatible for ETA inorganic materials (e.g. Sb2S3).
V. Pursue the understanding of interfaces, charge separation, electron transport and recombination through intensive computational modeling and transient spectroscopic, photoelectrochemical, and electronic analytical techniques. Understand the processes affecting long term stability in DSC operation under different stress conditions so that the materials and structural research and development activities can be effectively directed.
VI. Develop microscopically fine structures to minimize reflection losses from the FTO coated glasses, by means of the moths eye surface layer, in which the refractive index vary gradually from unity to that of the bulk material, reducing by up to 10% the losses of non perpendicular incident light. Introduce self-cleaning super-hydrophobic coatings for increased DSC operational lifetime. Assess the effectiveness of both approaches in the DSC framework.
VII. Achieve commercially viable longevity
via intensive and directed lifetime testing analysis and enhancement of device size cells, while remaining compatible with large area device fabrication procedures. Develop large-area deposition techniques for metal oxide semiconductors and low temperature materials processing. Investigate cell degradation mechanisms in real-scale modules.