Principles of luminescence

Abstract

Technologically important forms of luminescence may be broken into several categories, as shown in Table 1.1. Although the means by which the luminescence is excited varies, all luminescence is generated by means of accelerating charges. The portion of the electromagnetic spectrum visible to the human eye has wavelengths from 400 to 700 nm. The evolution of the relatively narrow sensitivity range of the human eye is a complex subject, but is intimately related to the solar spectrum, the absorbing behaviour of the terrestrial atmosphere, and the reflecting properties of organic materials, green being the dominant colour in nature and, not surprisingly, the wavelength at which the human eye is most sensitive. In this chapter, we cover the physical basis for radiation and radiation sources in solids that produce visible light.