• three-dimensional membranes;
  • polymer networks;
  • solvent trapping;
  • dye-sensitized solar cells;
  • physical stability;
  • long-term stability

A 3D polymer-network-membrane (3D-PNM) electrolyte is described for highly stable, solid-state dye-sensitized solar cells (DSCs) with excellent power-conversion efficiency (PCE). The 3D-PNM electrolyte is prepared by using one-pot in situ cross-linking polymerization on the surface of dye-sensitized TiO2 particles in the presence of redox species. This method allows the direct connection of the 3D-PNM to the surface of the TiO2 particles as well as the in situ preparation of the electrolyte gel during device assembly. There are two junction areas (liquid and solid-state junctions) in the DSCs that employ conventional polymer electrolytes, and the major interface is at the liquid-state junction. The solid-state junction is dominant in the DSCs that employ the 3D-PNM electrolyte, which exhibit almost constant performance during aging at 65 °C for over 700 h (17.0 to 17.2 mA cm–2). The best cell performance gives a PCE of 9.1%; this is slightly better than the performance of a DSC that employs a liquid electrolyte.