Research on scattering properties of phosphor for high power white light emitting diode based on Mie scattering theory

Abstract

Based on Mie scattering theory, the phosphor particle's scattering effect were simulated including light excitation and absorption. The light intensity proportion changes of forward and backward scattering light with different white light emitting diode (LED) color temperature were calculated. We also analyzed the phosphor particle size effecting the luminous flux of white LED and light color distribution of angle. Devices' excitation and emission spectrums used in our simulation were real measured spectrums of the material, rather than assuming a single spectrum. Our investigation discloses that when a conformal phosphor layer was adapted, phosphor particle diameter of 0.5 μm, makes maximum luminous flux and phosphor particles smaller, light color distribution of angel is better. While for given package structure, the best spatial color uniformity can be achieved with a phosphor layer thickness of 0.8 mm.