“…The combination of incident light and secondary light passing through the film forms white light. To that end, various polymerephosphor ) [11], GYAG [12], YAG:(Ce þ3 , Gd 3þ ) [13], YAG:(Ce þ3 ) [8,14e16] ) [18] particles dispersed in poly(-methyl methacrylate), Na 2 SO 4 [19] and BaAl x O y : (Eu 2þ , Dy 3þ ) [20] in low-density polyethylene, YAG:Ce þ3 in polydimethylsiloxane (PDMS) [21,22], and YBO 3 :(Eu 2þ ) [23] and YGG: (Tb 3þ ) [24] in a polyvinylpyrrolidone matrix. In any case, the goal is a stable white light with a high color rendering index (CRI) and high luminous efficacy as well as a light color that is stable and almost independent of the charged current.…”