TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Component: The perovskite-based thin-film solar cell has thin-film layer including a support layer, a dense layer formed between the substrate and support layer, an organic metal-semiconductor light-absorbing layer formed on the uppers surface of support layer, pair of electrodes formed on the organic metal-semiconductor light-absorbing layer, and a hole transport layer formed between pair of electrodes.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The material of support layer includes titanium dioxide, aluminum oxide, zirconium oxide or silicon dioxide, and is mixed with a pore-forming agent in a solvent, to form uniform dispersion of particles having a particle size of less than 1 mu m. The material of dense layer is titanium dioxide or zinc oxide. The material of electrodes includes gold, silver, copper and/or aluminum. The particulate material having particle size of less than 1 mu m of electrode is dissolved in solvent, to form uniform dispersion solution. The material of electrodes is carbon material or organic electroconductive compound. The carbon material is activated carbon, carbon black, graphite, graphene, spherical graphite, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon fiber and/or hard carbon material.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The material of organic metal-semiconductor light-absorbing layer is includes ammonium compound of formula: (RNH3)B'XmY'n (I). The organic metal-semiconductor light-absorbing layer is formed by printing ink including solution formed by dissolving material of organic metal-semiconductor light-absorbing layer in solvent. The solvent is chosen from ethanol, propanol, isopropanol, ethylene glycol, 1,2-propanediol, diethylene glycol, chlorobenzene, glycerol, terpineol, acetone, 1,4-dioxane, acetonitrile, 3-methoxy-propionitrile, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, pyridine, ethylenediamine, morpholine, carboxamide, acetamide, N-methylformamide, N,N- dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone and 1,4-butyrolactone.R=CH3, C4H9 or C8H9;B'=Pb or Sn;Y'=Cl, Br or I;m=1, 2 or 3;andn=3-m.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The material of hole transport layer is 2,2',7,7'-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene, poly(3-hexylthiophene-2,5-diyl), poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine), poly(N-9'-heptadecanyl-2,7carbazole-alt-3,6-bis(thiophen-5-yl)-2,5-dioctyl-2,5-dihydropyrrolo(3,4)pyrrole-1,4-dione), triphenylboron and/or ( alpha )-N,N'-bis-(1-naphthalenyl)-N,N'-bis-phenyl-(1,1'-biphenyl)-4,4'-diamine. The content of material of hole transport layer is 5-95 %mass.