Luminescent component

A luminescent component, comprising

• a first film comprising a first solid polymer composition, wherein the first solid polymer composition comprises first luminescent crystals, wherein the first luminescent crystals
• are of the perovskite structure,
• are selected from compounds of formula (I):
• M1aM2bXc (I), wherein
• M1 represents Cs, or Cs doped with up to 30 mol % of one or more other metals having coordination number 12,
• M2 represents Pb, or Pb doped with up to 30 mol % of one or more other metals having coordination number 6,
• X independently represents anions selected from the group consisting of CI, Br, I, cyanide, and thiocyanate,
• a represents 1,
• b represents 1,
• c represents 3;
• are of size between 3 nm and 3000 nm,
• emit red light in response to excitation by light with a shorter wavelength,
• a second film comprising a second solid polymer composition, wherein the second solid polymer composition comprises second luminescent crystals, wherein the second luminescent crystals
• are of the perovskite structure
• are selected from compounds of formula (II):
• M1aM2bXc (II), wherein
• M1 represents Cs, or Cs doped with up to 30 mol % of one or more other metals having coordination number 12,
• M2 represents Pb, or Pb doped with up to 30 mol % of one or more other metals having coordination number 6,
• X independently represents anions selected from the group consisting of CI, Br, and I, cyanide, and thiocyanate,
• a represents 1,
• b represents 1,
• c represents 3;
• are of size between 3 nm and 3000 nm,
• emit green light in response to excitation by light with a shorter wavelength, and
• one or more barrier films each having a water vapor transmission rate of less than 0.2 g mm m−2 day−1.