Abstract: A photoelectrochemical (PEC) device comprising two substrates, wherein: at least one substrates is transparent and coated with Transparent Electronic Conductor (TEC); a working electrode comprising dye sensitised porous semiconductor is formed on one substrate; a counter electrode comprising catalytic layer is formed on another substrate; electrolyte is placed between the two substrates; metallic conductor are utilized to conduct electrical current within and from the device; a protective layer of non-metallic material, with sufficient electrical conductivity to enable viable electrical output from the PEC device, is used to protect the metallic conductors from the electrolyte of the device.

Abstract: A nanophotocapacitive device wherein: a photovoltaic element (1) extends over substantially the whole area of the device, a charge storage element (3) also extends over substantially the whole area of the device, connection mechanism (14) are provided for interconnecting the photovoltaic and charge storage elements, the photovoltaic element comprises a nanoparticulate dye sensitized layer (11) of wide band gap semiconductor, a catalytic layer (13) and an electrolyte (12) placed between the semiconductor and the catalytic layers. The photovoltaic (photoelectrochemical) element and charge storage element (capacitor) are formed on opposite sides of a titanium foil substrate (8). Light (16) is incident on the transparent electrode (15). A diode (2) may be integral with the device to prevent the charge storage element discharging when there is no solar energy input to the photovoltaic element.