Security element with colour-producing nanostructures and production method therefor

A security element comprising:

• a structured layer comprising a base surface and recesses recessed or protrusions elevated relative to the base surface, and
• a reflector layer arranged on the structured layer,
• wherein the recesses or protrusions are formed as color-generating nanostructures with respect to their dimensions along the base surface, their vertical extension perpendicular to the base surface and their arrangement on the base surface,
• wherein the structured layer comprises a plurality of areas providing a colored motif or image, the areas forming pixels,
• wherein in each of the several areas the vertical extension of the recesses or protrusions varies along a direction according to a function that does not have a constant value, so that in each of the several areas in top view a color which is produced by the variation of the vertical extension is a mixed color.

A method for manufacturing a security element, the method comprising:

• creating a structured layer comprising a base surface and recesses recessed or protrusions elevated relative to the base surface, and
• arranging a reflector layer on the structured layer,
• wherein the recesses or protrusions are formed as a color-generating nanostructure with respect to their dimensions along the base surface, their vertical extension perpendicular to the base surface and their arrangement on the base surface,
• wherein the structured layer is formed with a plurality of areas which provide a coloured motif or image, the areas forming pixels, and
• wherein in each of the several areas the vertical extension of the recesses or protrusions along a direction varies according to a function that does not have a constant value, so that in each of the several areas in top view a color which is produced by the variation of the vertical extension is a mixed color.