Volatile solvent-free solid-state polymer-sensitized TiO2 solar cells with poly(3,4-ethylenedioxythiophene) as a hole-transporting medium

Novel, volatile solvent free, solid-state solar cells were fabricated with mesoporous TiO2 electrodes sensitized using thiophene derivatives containing carboxyl groups and in situ electropolymerized poly(3,4-ethylenedioxythiophene) as a hole-transporting material together with the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide and lithium bis(trifluoromethanesulfone)imide as additives for charge transport promotion