Electrochromic multi-layer devices with composite electrically conductive layers

An electrochromic device comprising a first substrate, a first electrically conductive layer, a first electrode layer, a second electrically conductive layer and a second substrate, at least one of the first and second electrically conductive layers comprising a patterned electrically conductive layer, the first and second electrically conductive layers each having a sheet resistance, Rs, to the flow of electrical current through the first and second electrically conductive layers that varies as a function of position in the first and second electrically conductive layers, respectively, wherein the ratio of the value of maximum sheet resistance, Rmax, to the value of minimum sheet resistance, Rmin, in the first electrically conductive layer is at least 2 and the ratio of the value of maximum sheet resistance, Rmax, to the value of minimum sheet resistance, Rmin, in the second electrically conductive layer is at least 2, the first substrate and the first electrically conductive layer being transmissive to electromagnetic radiation having a wavelength in the range of infrared to ultraviolet.

The electrochromic device of 17 wherein (i) the ratio of the average sheet resistance in a first region of the first electrically conductive layer circumscribed by a first convex polygon to the average sheet resistance in a second region of the first electrically conductive layer circumscribed by a second convex polygon is at least 2, the first and second regions of the first electrically conductive layer each comprising at least 25% of the surface area of the first electrically conductive layer and (ii) the ratio of the average sheet resistance in a first region of the second electrically conductive layer circumscribed by a first convex polygon to the average sheet resistance in a second region of the second electrically conductive layer circumscribed by a second convex polygon is at least 2, the first and second regions of the second electrically conductive layer each comprising at least 25% of the surface area of the second electrically conductive layer.

A process for the preparation of a multi-layer device comprising forming a multi-layer layer structure comprising an electrochromic layer between and in electrical contact with a first and a second electrically conductive layer, at least one of the first and second electrically conductive layers comprising a patterned electrically conductive layer, the first and/or the second electrically conductive layer having a spatially varying sheet resistance, Rs, to the flow of electrical current through the first and/or the second electrically conductive layer that varies as a function of position in the first and/or the second electrically conductive layer, respectively, wherein the ratio of the average sheet resistance in a first region of the first electrically conductive layer circumscribed by a first convex polygon to the average sheet resistance in a second region of the first electrically conductive layer circumscribed by a second convex polygon is at least 2, the first and second regions circumscribed by the first and second convex polygons, respectively, each comprising at least 25% of the surface area of the first electrically conductive layer.