Pseudo‐natural Light for Displays and Lighting

Light quality shows strong effects on humans in many aspects, including aesthetics, psychology, physiology, and health. By assuming that natural light has the best light quality, devising a pseudo-natural light is hence important and critical. Here, an all-weather pseudo-natural light is demonstrated based on a high number of broad-band emitters. By doping six broad-band organic light-emitting dyes in three separate emission layers, for example, the light source can exhibit a 92-96% similarity with the sunlight from dawn to dusk, and a color gamut of 80% in terms of NTSC. By combining six narrow-band light-emitting diodes (LEDs), a much wider gamut of 121% NTSC is achievable, but with a slightly poor daylight similarity, i.e., ranging between 80% and 83%. The daylight similarity, however, can easily be enhanced to at least 94% upon incorporating broad-band phosphors, even with the use of only one or two LEDs.