NOVELTY - Device comprises a layer structure with a titanium layer, a titanium dioxide layer arranged on the titanium layer, and a porous electrically conductive layer arranged on the titanium dioxide layer. The titanium dioxide layer is a conversion layer of the titanium layer, and titanium dioxide is in the form of rutile modification and in the form of anatase modification such that enclosed titanium dioxide layer comprising anatase is adjacent to the titanium layer. The porous titanium dioxide layer comprising rutile is arranged on the enclosed titanium dioxide layer comprising anatase.    USE - The device is useful for generating an electromotive force (claimed).    ADVANTAGE - The device is produced in simple and cost-efficient manner.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for producing a layer structure (10) for the above device, comprising (a) providing the titanium layer, (b) passivating the surface of the titanium layer by electrochemical oxidation using anodizing voltage (U1) of less than or equal to 71 V to form titanium dioxide layer as a passivating layer, (c) depositing titanium dioxide layer by electrochemical oxidation of titanium using anodizing voltage (U2) of 123 V, where anodizing voltage (U2) is greater than anodizing voltage, (d) forming a further titanium dioxide layer by electrochemical oxidation of titanium using anodizing voltage (U3) of less than or equal to 157 V, where anodizing voltage (U3) is greater than anodizing voltage (U2), (e) forming a further titanium dioxide layer by electrochemical oxidation of titanium using anodizing voltage (U4) of less than or equal to 170 V, where anodizing voltage (U4) is greater than anodizing voltage (U3), and (f) applying the electrically conductive layer on the titanium dioxide layer, where current flowing during oxidation is 200 mA in steps (b), (c), (d) and (e).    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of producing the layer structure for the device (Drawing includes non-English language text).    Time (12)    Surface of titanium layer (14)    alpha -Titanium crystallite (16)    Primary anatase layer degradation position (18)    Anatase to rutile thermal conversion position (20)