High-Efficiency White LED Packaging With Reduced Phosphor Concentration

In this letter, important factors for white light emitting diodes (LED) packaging, including lens encapsulation, reflectivity of cavity reflectors, and phosphor concentration are studied. Simulation as well as the corresponding experiment shows that reflectivity of the reflectors in packaging cavity is more effective than lens encapsulation to reach high efficiency. Besides, a white LED packaging without lens encapsulation but with high reflectivity of cavity reflectors may increase interaction possibility between blue photons and the phosphor so that the phosphor concentration can be reduced to meet the requested correlated color temperature.