The present invention relates to a method for producing titanium oxide particles, comprising a step of producing a mixed solution by mixing a hydrolysis product of a titanium alkoxide or a titanium metal salt and a compound having a five-membered ring containing nitrogen and a step of generating titanium oxide fine particles by heating and pressurizing the mixed solution, titanium oxide particles produced by the same production method, a dispersion solution of titanium oxide particles produced using the same titanium oxide particles, titanium oxide paste, a titanium oxide film, and a dye-sensitized solar cell.

The present invention is a method for forming a porous film of an inorganic substance on a base material by spraying fine particles of an inorganic substance on the base material such that the fine particles are bonded to the base material and bonded to one another, in which the fine particles include at least two kinds of fine particles which are small-size particles and large-size particles having different average particle sizes. According to the present invention, it is possible to provide a film forming method for forming a porous film formed of an inorganic substance without requiring a baking step, a body having a film formed thereon that is produced by the film forming method, and a dye-sensitized solar cell including the body having a film formed thereon.

Provided are an additive for an electrolytic composition which can suppress the decrease of a short-circuit current and improve an open circuit voltage as compared to the case when conventional 4-TBpy is used as an additive for an electrolytic composition, and an electrolytic composition using this additive and a dye-sensitized solar cell. The additive for an electrolytic composition for use in a dye-sensitized solar cell contains a pyridine derivative having a pyridine ring into which an alkylsilyl group is introduced, and it is preferable that this pyridine derivative has an alkylsilyl group at the 4-position of the pyridine ring, and it is more preferable that the pyridine derivative is 4-(trimethylsilyl) pyridine.

The present invention concerns an organic dye comprising a photochromic entity, a segment -eD representing an electron donor segment and a segment -L-A with -L- representing a covalent bond or a spacer segment and particularly a pi-conjugated spacer segment, and -A representing an electron attractor segment able to form a covalent bond with a semi-conductor. The present invention concerns the use thereof as photosensitizer in a photovoltaic device and said photovoltaic device.

The present invention relates to a photoelectrode for a dye-sensitized solar cell including inorganic nanoparticles, wherein a three-dimensional pattern is formed on the surface of the photoelectrode. The three-dimensional photoelectrode for a dye-sensitized solar cell according to the present invention has a micrometer-sized pattern and thus exhibits an improved light absorption caused by a total reflection and a increased light path.

Disclosed is a photoelectrochemical cell to convert solar energy into electrical energy and to a process for the realization of the photoelectrochemical cell. The photoelectrochemical cell includes: —a first conductive external membrane; —a nanomembrane fixed to the first membrane and including titanium dioxide; —a natural pigment absorbed in the nanomembrane; —a second conductive external membrane disposed in an opposite position to the first membrane; an electrolyte, disposed between the nanomembrane and the second membrane.

The invention relates to the use of halogenated histidine derivatives as electrolyte salts in the preparation of an electrolyte composition in a photoelectrochemical cell based on the sensitization to light of photoactive molecules, and also to a photoelectrochemical cell based on the sensitization to light of photoactive molecules comprising an electrolyte composition comprising at least one halogenated histidine derivative as electrolyte salt.

Disclosed is a photoelectric conversion element including a cell. The cell includes a first electrode, a second electrode, an oxide semiconductor layer provided on the first electrode, and an electrolyte provided between the first and second electrodes. The second electrode includes an annular portion, an approaching portion approaching the oxide semiconductor layer closer than the annular portion and an annular connecting portion connecting the annular portion and the approaching portion, and the oxide semiconductor layer includes an inner part facing the approaching portion on the first electrode and an annular outer part provided around the inner part and facing the connecting portion. The outer part includes a plurality of linear portions separated from one another and a corner portion connecting two adjacent linear portions to each other, the corner portion is thicker than the linear portion, and the linear portion is thicker than the inner part.

Provided are a photoelectric conversion element having a photosensitive layer including a light absorber, in which the light absorber includes a compound having a perovskite-type crystal structure including specific cations and anions, and at least some of the anions constituting the compound are organic anions represented by Formula (An) and a solar cell using this photoelectric conversion element.

R.sup.1—C(═X.sup.1)—X.sup.2  Formula (An) R.sup.1 represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an aliphatic heterocyclic group, —N(R.sup.2).sub.2, —OR.sup.3, —SR.sup.4, or a halogen atom. X.sup.1 represents an O atom or a S atom. X.sup.2 represents O.sup.− or S.sup.−. R.sup.2 to R.sup.4 are specific groups. Here, in a case in which X.sup.1 is an O atom and X.sup.2 is O.sup.−, R.sup.1 is a specific group.

Titanium dioxide and an electro-conductive titanium oxide which each includes particles having a large major-axis length in a large proportion and comprises columnar particles having a satisfactory particle size distribution. A titanium compound, an alkali metal compound, and an oxyphosphorus compound are heated/fired in the presence of titanium dioxide nucleus crystals having an aspect ratio of 2 or higher to grow the titanium dioxide nucleus crystals. Subsequently, a titanium compound, an alkali metal compound, and an oxyphosphorus compound are further added and heated/fired in the presence of the grown titanium dioxide nucleus crystals. Thus, titanium dioxide is produced which comprises columnar particles having a weight-average major-axis length of 7.0-15.0 μm and in which particles having a major-axis length of 10 μm or longer account for 15 wt. % or more of all the particles. A solution of a tin compound and a solution of compounds of antimony, phosphorus, etc. are added to a suspension obtained by suspending the titanium dioxide. The particles are sedimented. Subsequently, the product obtained is heated/fired to produce an electro-conductive titanium oxide which comprises the titanium dioxide and an electro-conductive coating formed on the surface thereof.