Light-emitting electrochemical cell, security element, security system, method of operation and method of production

A method of operating a light-emitting electrochemical cell comprising:

• a substrate,
• a first electrode,
• an emission layer, contacting the first electrode and providing a first two-dimensional (2D) pattern, which is made up by the emission layer being visually distinguishable from the substrate and/or one or more components associated with the light-emitting electrochemical cell, and
• a second electrode,
• wherein the emission layer provides a second 2D pattern, which is made up by first portions which are passive with respect to photoluminescence and second portions of the emission layer which are active with respect to photoluminescence,
• wherein a third 2D pattern is provided by regions, which are active with respect to electroluminescence, where the first and second electrodes overlap and electrically contact the second portions of the emission layer,
• the method comprising:
• providing the light-emitting electrochemical cell with only the first 2D pattern being visually distinguishable,
• exposing the light-emitting electrochemical cell to first excitation light, whereby the second portions of the emission layer are caused to provide photoluminescence, such that the second 2D pattern becomes visually distinguishable, and
• electrically operating the light-emitting electrochemical cell so as to cause electroluminescence in said emission layer by applying an electric potential across the electrodes, such that the third 2D pattern becomes visually distinguishable.

A method of manufacturing a light-emitting electrochemical cell, comprising:

• providing a substrate,
• depositing a first electrode on the substrate,
• depositing an emission layer, which contacts and at least partially overlaps the first electrode, to provide a first two-dimensional (2D) pattern, which is made up by emission layer being visually distinguishable from the substrate and/or one or more components associated with the light-emitting electrochemical cell,
• providing a second 2D pattern, which is made up by first portions which are passive with respect to photoluminescence and second portions of the emission layer which are active with respect to photoluminescence, and
• depositing a second electrode, which contacts and at least partially overlaps the emission layer, and which at least partially overlaps the first electrode, to form regions which are active with respect to electroluminescence.