Fig. 4: Historical improvements in consumer experience metrics of phosphor-converted white LED devices.
Data points show the CT and CRI of the earliest identified commercially available white LED products with published spectral data that used phosphors listed in Table 1, each indicated by the phosphor label and publication year. Horizontal lines represent typical CTs of ‘traditional’ light sources, shown for reference. The desirable range of colour temperatures for home illumination, indicated by a vertical red arrow, lies between two horizontal orange lines representing typical incandescent light and warm daylight colour temperatures. The horizontal red arrow indicates desirable higher CRI values. Source: own calculations based on spectral data provided in Supplementary Note 5 for white LED products with the following phosphors: YAG37, YGAG68, 25880, SLA90, PFS87, QD95,96, SALON38.
