Abstract: An electrochromic or photoelectrochromic device possessing the property of changing color under the effect of an electric voltage and/or of a variation in the intensity of a light radiation, this device comprising at least one cathode and one anode, at least one of these electrodes being constituted at least in part of a transparent or translucent substrate bearing an electrically conductive coating, and an electrolyte arranged between these electrodes, and an electric circuit connecting said cathode and anode, characterized in that at least one of these electrodes carries a coating constituted of at least one nanocrystalline layer of at least one semiconductive material, having a roughness factor equal to at least 20, and a monolayer of electrically active molecules or of an electrically active polymer, said monolayer being absorbed on the surface of this coating, and in that the device contains at least one auxiliary electrically active compound, possibly dissolved in the electrolyte, having the property of

Abstract: Electrochromic and photoelectrochromic devices using nanocrystalline semiconductor electrodes with a high specific surface area and surface-absorbed electrochromic molecules are disclosed.

Abstract: Electrochromic and photoelectrochromic devices using nanocrystalline semiconductor electrodes with a high specific surface area and surface-absorbed electrochromic molecules are disclosed.

Abstract: A cell including a photoanode consisting of at least one polycrystalline titanium dioxide layer on a conductive substrate, a counter-electrode and an electrolyte positioned between these electrodes, at least one of said electrodes being transparent or translucent. The electrolyte includes an oxidation-reduction system which is liquid at room temperature. The first species of the pair making up the oxidation-reduction system advantageously consists of an electrochemically active salt having a melting point below room temperature, and optionally being dissolved in at least one electrochemically inactive salt also having a melting point below room temperature.

Abstract: Hydrophobic liquid salts of the general formula ##STR1## in which R.sub.1 and R.sub.3 are the same or different and each represent a straight or branched chain alkyl radical, a fluoroalkyl radical or an alkoxyalkyl radical of 1 to 8 carbon atoms; and R.sub.2, R.sub.4, and R.sub.5 are the same or different and each represent a hydrogen atom or an alkyl radical with 1 to 3 carbon atoms.The invention has applications as an electrolyte solvent in electrochemical photovoltaic cells.