Abstract
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. An all-weather pseudo-natural light based on a high number of broad-band emitters is demonstrated. By doping six broad-band organic light-emitting dyes into three separate emission layers, for example, the light source can exhibit a 92-96% similarity with sunlight from dawn to dusk.