TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The porosity of porous semiconductor layer is 45-70%. The semiconductor granules have grain diameters of 1-100 nm; and are titanium dioxide granules, silicon dioxide granules, yttrium oxide granules, lanthanum oxide granules, hafnium oxide granules, strontium oxide granules, vanadium pentoxide granules, chromium oxide granules, molybdenum oxide granules, magnesium oxide granules, scandium oxide granules, samarium oxide granules, gadolinium oxide granules, strontium titanate granules, zinc sulfide granules, lead sulfide granules and/or cadmium sulfide granules. The conductive bottom layer is a conductive glass with surface having fluorine-doped tin dioxide film or indium tin oxide doped film; and has 0.5-5 mm thickness. A face of conductive bottom layer, contacting the porous semiconductor layer, is the surface. The pore forming agent is an inorganic compound which cannot be dissolved in water but can be dissolved in acid, or inorganic compound which cannot be dissolved in water but can be dissolved in alkali. The inorganic compound which cannot be dissolved in water but can be dissolved in acid comprises carbonate of magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), cadmium (Cd), lead (Pb) or silver (Ag); oxalates of Mg, Ca, Sr, Ba, iron (Fe), nickel (Ni), cobalt (Co), copper (Cu), Ag, zinc (Zn), Cd, bismuth (Bi) or Pb; oxides of Mg, boron (B), gallium (Ga), indium (In), Pb, Bi, Zn, Cu, Ag, Cd, Mn, Fe, Co, Ni or antimony (Sb); hydroxides of Mg, B, Ga, In, Pb, Bi, Zn, Cu, Ag, Cd, Mn, Fe, Co, Ni or Sb; sulfides of Ca, Sr, Ba, titanium (Ti), Fe, Co, Ni, Cu, Cd, Ag, zirconium, yttrium, tin, Bi, Sb, Pb or In; nitrides or oxyhalides of Ti, vanadium, chromium, Fe or In; and/or oxyhalides of Bi, Sb or Pb. The inorganic compound which cannot be dissolved in water but can be dissolved in alkali comprises hydroxides of Cu, Ag, gold, Zn, Bi, Pb, Ni, Fe, manganese, platinum, palladium, rhodium, iridium, B, aluminum, silicon, germanium, Sb, molybdenum and/or tungsten. A volume ratio of pore forming agent and semiconductor granules is 1:1-99 (preferably 1:1.5-15). When the pore forming agent is inorganic compound which cannot be dissolved in water but can be dissolved in acid, the solution is nitric acid, hydrochloric acid and/or sulfuric acid and has pH 0.5-6. When the pore forming agent is inorganic compound which cannot be dissolved in water but can be dissolved in alkali, the solution is aqueous solution of sodium hydroxide or potassium hydroxide and has pH 8-13.5. A mass ratio of dispersant to semiconductor granules is 0.5-8:100. Preferred Process: The first calcining step is carried out for 10-120 minutes at 300-600 degrees C. The second calcining step is carried out for 30-180 minutes at 400-500 degrees C.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The dye layer contains light sensitized dye selected from ruthenium pyridine complex, porphyrin complex, phthalocyanine complex and/or non-metallic organic dye.