Mormally 0.5 M TBP should be added in the electrolyte. And some ioic liquid is usually added to enhance the conductivity of electrolyte for DSSCs.

Electrolyte solution giving the highest efficiency.

J. AM. CHEM. SOC. 2005, 127, 16835

Electrolyte solution, A6141 is composed of 0.6 M M-methyl-N-butyl imidiazolium iodide, 0.03 M iodine, 0.1 M guanidinium thiocyanate (GuNCS) and 0.5 M tert-butylpyridine (TBP) in 15/ 85 (v/v) mixture of valeronitrile and acetonitrile.

Jpn. J. Appl. Phys., 45 (2006) L638

Electrolyte, M1 consists of 0.6 M M-methyl-N-butyl imidiazolium iodide, 0.04 M iodine, 0.025 M LiI, 0.05 M GuNCS and 0.28 M TBP in 15/85 (v/v) mixture of valeronitrile and acetonitrile.