A device for storing electrical energy comprises a photo electrode, having a semiconductor layer with a photo dye thereon, a counter electrode, a reservoir comprising a solvent, a first redox mediator for enabling a redox reaction at the photo electrode, a second redox mediator for enabling a redox reaction at the counter electrode, wherein the photo electrode and the counter electrode are at least partly in the solvent, the first redox mediator is adapted to form an entity that is soluble in the solvent when the first redox mediator is in its reduced state, and an entity that is insoluble in the solvent when the first redox mediator is in its oxidized state.

A photoelectric conversion element having an electrically conductive support, a photoconductor layer including an electrolyte, a charge transfer layer including an electrolyte, and a counter electrode, in which the photoconductor layer has semiconductor fine particles carrying a metal complex dye represented by the following Formula (1), and a dye-sensitized solar cell; and a metal complex dye and a dye solution, each of which is used in the photoelectric conversion element and the dye-sensitized solar cell,

ML1L2(X).sub.n1.CI.sub.mYFormula (1) in the formula, M represents a metal ion, L1 represents a tridentate ligand having a group L.sup.V represented by the following Formula (LV-1) or (LV-2); L2 represents a bidentate or tridentate ligand including at least one of aromatic ring groups having a specific sp.sup.2 carbon atom to which a substituent is bonded; X represents a monodentate ligand; n1 represents 0 or 1; CI represents a required counterion; and mY represents an integer of 0 to 3,

R.sup.V1R.sup.V2R.sup.V31Formula (LV-1)

CCR.sup.V32Formula (LV-2) in the formulae, R.sup.V1 and R.sup.V2 each independently represent a nitrogen atom or CR.sup.V4, R.sup.V4 represents a hydrogen atom or a substituent, R.sup.V31 represents a fused polycyclic aromatic ring group or a fused polycyclic heterocyclic group, and R.sup.V32 represents a fused polycyclic aromatic ring group or a heteroaryl group.

A doped organic semiconductor is produced using the method of providing an organic semiconductor solution, contacting the organic semiconductor solution with CO.sub.2; and irradiating the organic semiconductor solution with ultraviolet light. A composition is described, the composition comprising an organic semiconductor; and a metal salt having the formula M.sup.+X.sup. wherein X.sup. is a monoanionic species; and wherein the ratio of M.sup.+ to X.sup. in the hole transport material is less than about 1.00. An additional composition is described, the composition comprising an organic semiconductor; a metal salt having the formula M.sup.+X.sup. wherein X.sup. is a monoanionic species; and a metal carbonate; wherein the total metal content of the composition is approximately equal to the X.sup. content of the composition.

A photoelectrochemical system and method utilizing the photons having energies above the bandgaps of a p-type semiconductor photocathode and an n-type semiconductor photoanode with redox couples having fast electron transfer kinetics to keep overpotentials under 0.15 volts, and redox potentials energetically located within the band gaps, for storing energy in photodriven oxidation and reduction reactions separated by less than 1.6 volts using a redox flow battery configuration, are described. The photoelectrochemical system can also store heat in the flow battery generated from the inefficiencies of the photoredox reactions and from impinging photons having energies below the band gaps. Redox flow batteries contain fluid electrolyte and tanks for storing the redox equivalents, which can be used to store the solar energy not used to drive the photoredox chemistry for hot water and space heating applications. The present hybrid photoelectrochemical/thermal system may be used store excess grid electricity when electrical demand is low, or as a conventional redox flow battery in a distributed energy system, if the redox electrolyte volume was increased above that needed for solar load leveling on a daily or weekly time scale. Heat generated from the discharge of the redox battery would also be captured and stored.

Provided is a photoelectric conversion element including a first electrode, a hole blocking layer, an electron transport layer, a first hole transport layer, and a second electrode, wherein the first hole transport layer includes at least one of basic compounds represented by general formula (1a) and general formula (1b) below:

##STR00001##

where in the formula (1a) or (1b), R.sub.1 and R.sub.2 represent a substituted or unsubstituted alkyl group or aromatic hydrocarbon group and may be identical or different, and R.sub.1 and R.sub.2 may bind with each other to form a substituted or unsubstituted heterocyclic group containing a nitrogen atom.

A method of ligand-induced regional modification of a perovskite film of perovskite optoelectronic device can include generating a ligand atmosphere, exposing a perovskite optoelectronic device in the ligand atmosphere, and removing the perovskite optoelectronic device from the ligand atmosphere. Methods for improving the performance and stability of perovskite optoelectronic devices are performed by using a ligand-induced modification of complete devices at room temperature. This post-device treatment, completely separated from the fabrication process of common perovskite optoelectronic devices, provides a general strategy to improve the stability of different completed perovskite optoelectronic devices (i.e., perovskite solar cells, perovskite light-emitting diodes, and photodetectors) without introducing any undesirable impurities during device fabrication.

The present disclosure may provide semiconductor perovskite layers and method of making thereof. In some cases, the perovskite layer may comprise a composition of MA.sub.n1FA.sub.n2Cs.sub.n3PbX.sub.3. MA may be methylammonium, FA may be formamidinium, n1, n2, and n3 may independently be greater than 0 and less than 1, and n1+n2+n3 may equal 1.

The invention relates to electrochemical devices comprising complexes of cobalt comprising at least one ligand with a 5- or six membered, N-containing heteroring. The complex are useful as p- and n-dopants, as over of electrochemical devices, in particular in organic semiconductors. The complexes are further useful as over-discharge prevention and overvoltage protection agents.

A solar cell according to the present disclosure includes a first electrode, a second electrode, a photoelectric conversion layer disposed between the first electrode and the second electrode, and an electron transport layer disposed between the first electrode and the photoelectric conversion layer. At least one electrode selected from the group consisting of the first electrode and the second electrode has a light-transmitting property. The photoelectric conversion layer contains a perovskite compound comprising a monovalent cation, a Sn cation, and a halogen anion. The electron transport layer contains porous TiZnO.sub.3.

The teachings herein pertain to hole transporting compounds containing a cyclobutyl moiety, which can be made into organic hole conductors and into hole transporting material. Additionally, optoelectronic and photoelectrochemical devices comprising such hole transporting material or hole transporting compound are described, in particular photovoltaic devices, organic-inorganic perovskite films, layered photovoltaic devices, p-n heterojunctions, dye-sensitized solar cells, organic solar cells and solid-state solar cells. Notably, a fabricated perovskite solar cell module using a disclosed HTM compound exhibited a record efficiency over 19.0% with an active area of 30.24 cm.sup.2.