TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The perovskite is of formula: CMX3, where C is one or more cations chosen from Group 1 metals, Group 2 metals, and/or organic cations, M is one or more metals chosen from iron, cobalt, nickel, copper, tin, lead, bismuth, germanium, titanium and zinc, preferably lead, and X is one or more anions chosen from halide and Group 16 anions, preferably halides. The C of perovskite comprises methyl ammonium and/or strontium, and M comprises titanium, and X comprises oxygen. The active layer further comprises photoactive material chosen from dye, silicon, cadmium telluride, cadmium sulfide, cadmium selenide, copper indium gallium selenide, gallium arsenide, germanium indium phosphide, and/or semiconducting polymer.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The dye comprises a primary electron donor moiety comprising at least one substituent chosen from aryl amine, aryl phosphine, aryl arsine, aryl stibine, aryl sulfide, aryl selenide, phenyl, phenol, alkoxy phenyl, dialkoxy phenyl, and alkyl phenyl, a core moiety comprising at least one aryl substituent chosen from nitrogen heterocyclic compound, benzothiophene, dibenzothiophene, naphthothiophene, dinaphthothiophene, benzonaphthothiophene, naphthyl, benzothiazole, benzothiadiazole, benzo(b)naphtha(2,3-d)thiophene, 4H-cyclopenta(l,2-b:5,4-b')bisthiophene, dinaphtho(2,3-d)thiophene, thieno(3,2-b)thiophene, naphthalene, and anthracene, a secondary electron donor moiety comprising at least one pi-electron donor substituent chosen from thiophene, benzothiadiazole, benzene, benzothiophene and thienothiophene, and an electron-withdrawing moiety comprising at least one substituent chosen from carboxylic acid, monocyanocomplex, dicyanocomplex, thiocyanocomplex and isothiocyanocomplex. The interfacial layer of photovoltaic cell comprises oxides, sulfides, nitrides of aluminum, bismuth, indium, molybdenum, nickel, platinum, silicon, titanium, vanadium, niobium, zinc, alkyl silyl groups, graphite, graphene, fullerenes and/or carbon nanotubes. The active layer further comprises a mesoporous layer (3904) comprising pore-containing material chosen from nitride of aluminum, bismuth, indium, molybdenum, niobium, nickel, platinum, silicon, titanium, vanadium, and zinc, treated asphaltenes, titania/metal-oxide bilayer, alkyl silyl groups, graphite, graphene, fullerenes, and/or carbon nanotubes. The copper-oxide compound is of formula: CuxOy, where x is 1-3, and y is 0.1-2. Preferred Properties: The copper-oxide compound comprises nanoparticles having particle size of 50 nm or less. The charge-transporting compound comprises nanoparticles having particle size of 50 nm or less.