NOVELTY - Phosphate ester electrolyte solvent that is used on dye-sensitized solar cell comprising H, CN, or 1-12C alkyl replaced by CN, is new.    USE - The phosphate ester electrolyte solvent is useful on dye-sensitized solar cell (claimed).    ADVANTAGE - The electrolyte solvent has high boiling point, wide temperature scope of application, and is hard to volatilize, thus the useful time of cell is increased. Additionally, it is very stable, cost-effective, and has simple synthesis, thus it is beneficial to the production and practical application of cells.    DETAILED DESCRIPTION - Phosphate ester electrolyte solvent of Formula 1 that is used on dye-sensitized solar cell, is new. (I)    R1 and R2=H, CN, or 1-12C alkyl replaced by CN;    R3=1-12C alkyl or 1-12C alkyl replaced by CN; and    n=0-12.    An INDEPENDENT CLAIM is the use of phosphate ester electrolyte solvent on dye-sensitized solar cell comprising:(a) confecting of electrolyte solution, where phosphate ester compound is placed into container, and iodized salt (imidazole-derivative iodized salt, quaternary ammonium iodized salt, or metallic iodide) with concentration of 0.01-5 moles/L, iodine gas (I2) and 0.01-5 moles/L of additive are added to make mole ratio of iodized salt and iodine ion to be 1:0.001-0.5, and it is mixed evenly by heating and stirring at 20-150 degrees C or by ultrasonic concussion at room temperature; (b) preparation of dye-sensitized solar cell, where the preparation of cell is pre-treating conductive glass, and then coating titanium dioxide slurry onto treated conductive glass, and after high temperature treatment, dyestuff is immersed for adsorption for 14-24 hours to form working electrode of cell, and confected electrolyte solution is capsulated between the counter electrode of the working electrode and platinum through sealing glue to be prepared into dye-sensitized solar cell; and (c) testing of cell property, where testing of cell property is leading out conducting wire from the working electrode and counter electrode of the cell, and connecting it to the testing device for cell property, where the working area of the cell is decided by a dummy plate with hole area of 0.159 cm2, solar light imitator is used to imitate solar light, the light intensity is adjusted to 100 milliWatts (mW)/cm2, the tested cell discharge curve, light-electricity converting efficiency is 0.57%-4.37%, circuital current is 6.58-12.1 milli-Amperes per square centimeter, open-circuit voltage is 273-761 milli-volts, and filling factor is 0.28-0.66.