TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - The sensitizing agent comprises at least one inorganic light absorbing thin film or semiconductor nanoparticle layer formed from a material selected from PbS, PbSe, SnS, SnSe SbS, SbSe, CdSe, Ge, Si. The ionic additive is lithium salt such as lithium bis(trifluoromethylsulfonyl)imide salt (Li-TFSI) or Li perchlorate; and is a mixture of a metal salt and an ionic liquid. The n-type semiconductor material comprises at least one single metal oxide, compound metal oxide, doped metal oxide, carbonate, sulfide, selenide, teluride, nitrides and/or multicompound semiconductor (preferably TiO2, SnO2 or ZnO). The n-type material is selected from oxides of Ti, Zn, Sn, and/or W, and where the n-type material is optionally surface coated. The ionic materials comprise at least one metal salt (preferably at least one lithium salt), and at least one ionic liquid (preferably 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - The sensitizing agent comprises at least one dye selected from ruthenium complex dye, metal-phalocianine complex dye, metal-porphryin complex dye, squarine dye, thiophene based dye, fluorine based dye, and/or polymer dye. The ionic additive comprises or consists of an ionic liquid, selected from 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-allyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1,3-dihydroxy-2-methylimidazolium bis(trifluoromethylsulfonyl)imide, and/or 1,3-dimethoxy-2-methylimidazolium bis(trifluoromethylsulfonyl)imide.    TECHNOLOGY FOCUS - POLYMERS - The organic p-type material is an organic polymer (preferably conducting polymer or semi-conducting polymer). The p-type material is an organic polymer selected from poly thiophenes and/or poly para-phenylene vinylenes, or their derivatives and their copolymers (preferably poly thiophene); and is an organic polymer having a molecular weight of greater than 15000.