Inverted-Cone-Lens Encapsulant With Gradient Surface for Ring-Remote-Phosphor…

The ordinary ring-remote-phosphor structure consisting of an inverted-cone-lens encapsulant and a surrounding ring-remote-phosphor layer reduces the probability of the backward light from the phosphor layer to the absorptive lightemitting diode (LED) chip and then increases the package extraction efficiency. However, some of the blue light emitting from the LED chip impinges on the inverted-co…