TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Device: The photovoltaic solid state device further comprises an organic-inorganic perovskite as sensitizer, the sensitizer being under the form of a layer. The organic-inorganic perovskite layer material comprises a perovskite-structure of any one of Formulas AA'MX4 (IV), AMX3 (V), AA'N'2/3X4 (VI), AN'2/3X3 (VII), B'N'2/3X4 (VIII) and B'MX4 (IX).A and A'=organic, monovalent cations that are independently selected from primary, secondary, tertiary or quaternary organic ammonium compounds, including N-containing hetero rings and ring systems, A and A' having independently from 1-60 carbons and 1-20 heteroatoms;B'=an organic, bivalent cation selected from primary, secondary, tertiary or quaternary organic ammonium compounds having 1-60 carbons and 2-20 heteroatoms and having two positively charged nitrogen atoms;M=a divalent metal cation selected from Cu2+, Ni2+, Co2+, Fe2+, Mn2+, Cr2+, Pd2+, Cd2+, Ge2+, Sn2+, Pb2+, Eu2+, or Yb2+;N'=Bi3+ and Sb3+; andX=Cl-, Br-, I-, NCS-, CN-, and NCO-. Preferred Definitions:    E1, E2, E4 and E5=identical moieties selected from O, S, Se, CR2, SiR2 and NR;    E3=a moiety selected from O, S, Se, CR2, SiR2 and NR;    R=1-20C alkyl, 2-20C alkenyl, 2-20C alkynyl, 4-20C aryl, 2-20C acetyl and 1-20C fluoroalkyl group, where the alkyl, alkenyl, alkynyl, acetyl and fluoroalkyl, if they comprise 3 or more carbons may be linear, branched or cyclic and where aryl group may be substituted;    Ar1 and Ar2=a moiety according to any one of the Formulas (1) to (19);    W'=O, S, Se, or NR;    Y', V', K' and D=C, N, S, Se, O, CR2, SiR2 or NR, preferably V' is independently selected from O, S or Se, and K' and D are independently selected form C, O or N;    G=C or Si;    n=1-10;    R3-R18=H, 1-20C alkyl, 1-20C alkoxy, 2-20C alkenyl;    Z=a moiety according to any one of the Formulas (20)-(34) and (58)-(66);    COOR20=a carboxylic ester derivative;    R20=1-20C alkyl groups; and    R19, R21, R22 and R25=H, 1-20C alkyl, 1-20C alkoxy, 2-20C alkenyl, 2-20C alkynyl, 1-20C fluoroalkyl group and 4-20C aryl, where the alkyl, alkenyl, alkoxy, alkynyl and fluoroalkyl, if they comprise 3 or more carbons may be linear, branched or cyclic and where aryl group may be substituted.    EXAMPLE - No suitable example given.