Electric lighting is a significant part of the energy consumption in buildings. Driven by the rising energy demand, the contribution of lighting to energy consumption is anticipated to grow. In the last decades, this growing energy demand forced governments and manufacturers to think about alternative ways of generating electric lighting. Promising developments in the lighting industry, such as the introduction of solid-state lighting (SSL) devices for general lighting, made a huge impact. SSL devices have several advantages over previous lighting technologies, such as compact size, longer lifetime, directionality, high efficacy, ease of control of light output, and high color quality.
Spectral power distribution (SPD), radiant power as a function of wavelength, is a crucial part of luminous efficacy and quantification of the color quality of a light source. The color appearance of an object is constituted by the light source spectrum, the object’s spectral reflectance, and the human visual