Fig. 6. (a) Scheme of PPC films with different colors used as exchangeable down-conversion sheets in lighting applications. Fitted spectra for (b) sunlight like or (c) incandescent light like lighting using PPCs' PL spectra of different emitting wavelengths. (d) Photograph of a 5′′ by 3′′ transparent green PPC film under ambient light, in front of the text. (e) Photograph of the transparent projection display. (f) Luminescence at different viewing angles.