With the increasing of the viscosity of electrolyte, the diffusion coefficient of I_3 ion decreased rapidly to be a new controlling step in the quasi-solid state dye-sensitized solar cell.

Solid quasi-fluid state, which is similar to liquid and exists in surface and interior of solid, is one new kind of state besides gas, liquid and solid state.

By using concept as quasi classical particles, the particles which move in a large range of space in solid state are described.