Light-emitting diode

摘要

A light-emitting diode, comprises an active layer for emitting a light with a phase and a peak wavelength λ in air, a reflector, a lower semiconductor stack between the active layer and the reflector, wherein the lower semiconductor stack comprises multiple semiconductor layers, and each of the multiple semiconductor layers has a refractive index ni, a thickness di and two sides each contacting adjacent layers to form two interfaces, wherein each interface has a phase shift when the light passes through the interface.

主权项

1. A light-emitting diode, comprising:
an active layer for emitting a light ray with a phase and a peak wavelength λ in air; an upper semiconductor stack on the active layer; a reflector; and a lower semiconductor stack between the active layer and the reflector, wherein the lower semiconductor stack comprises multiple semiconductor layers, and each of the multiple semiconductor layers has a refractive index ni, a thickness di and two sides each contacting adjacent layers to form two interfaces, wherein each interface has a phase shift when the light ray travels through the two interfaces along a same direction, and wherein, for one of the multiple semiconductor layers traveled through by the light ray, the thickness di satisfies at least one of the following conditions of:
(i) if the two phase shifts are the same, then 0.8*((2m−1)/2)*(λ/ni)≦di≦1.2*((2m−1)/2)*(λ/ni), where m is a natural number; and(ii) if the two phase shifts are different, then 0.8*((2m−1)/4)*(λ/ni)≦di≦1.2*((2m−1)/4)*(λ/ni), where m is a natural number.