Hiroyasu Sumino

Quasi-solid dye-sensitized solar cells containing chemically cross-linked gel: How to make gels with a small amount of gelator

Quasi-solid dye-sensitized solar cells equipped with chemically cross-linked gels are reported. The gelator contains multi-functional pyridine or imidazole derivatives and multifunctional halogen derivatives. The former reacts with the latter to give three-dimensional ionomer structures even in liquid electrolytes. Gelators polymerized directly in liquid electrolytes of cells have not been reported so far. This makes the cell fabrication process easier, where electrolyte precursors are injected into cells, followed by gelled directly in the cells. In addition, a micro-phase separation technique is introduced in order to decrease the amount of gelators. This makes it possible for the liquid electrolytes to be solidified without losing the high performance of liquid-type cells before gelation.

Quasi-solid dye sensitised solar cells filled with phase-separated chemically cross-linked ionic gels

Quasi-solid dye sensitised solar cells were prepared by gelling ionic liquid electrolytes with phase-separated chemically cross-linked gels which make it possible to solidify DSSC without losing the performance of the parent DSSC.

Quasi-solid dye-sensitized solar cells: control of TiO2-gel electrolyte interfaces

Quasi-solid dye sensitized solar cells (Q-DSSC) were fabricated by employing gel electrolytes containing ionic liquids and gelators. Sufficient physical contacts between nano-crystalline TiO2 particles and gel electrolytes in nano-porous TiO2 layers were achieved by solidifying gel electrolyte precursors after the cells are filled with the electrolytes. Photo-currents increased largely by embedding carboxylic acids among dye molecules on TiO2 crystals. The nano-porous TiO2 electrolytes were fabricated by dipping the dye anchored TiO2 substrates in dilute solutions of carboxylic acids. It was found that resistances in the TiO2 layers decreased by these treatments.