Effect pigments having a reflective core and semiconductor layers

A method of manufacturing an effect pigment using a PVD process comprising:

• a) coating a thin, flexible substrate with a release coat agent,
• b) depositing a first semiconductor layer onto the flexible substrate using a roll-to-roll process,
• c) depositing a layer of a highly reflective metal onto the first semiconductor layer,
• d) depositing a second semiconductor layer onto the highly reflective metal layer, and
• e) stripping the material stack from the flexible substrate in a solvent;
• the resulting effect pigment having a layer stack which comprises a highly reflective metallic flake having a first major interface and opposed to this first interface a second major interface, and at least one side surface and directly adjacent on one or of both of these major interfaces a layer of a semiconducting material having an average atomic composition of:
• a) Si(1-x)Snx, wherein 0<x<0.90 or
• b) Ge(1-y)Sny, wherein 0<y≤0.80 or
• c) Si(1-m-n)GemSnn, wherein 0<m<1.00, 0<n<1.00 and with the proviso that m+n<1.00.