Patent ID: 8809886

Claim:
A light emitting diode comprising: a substrate; a source layer comprising a first semiconductor layer, an active layer, and a second semiconductor layer stacked on a surface of the substrate in the listed sequence; a first electrode electrically connected with first semiconductor layer; a second electrode electrically connected with the second semiconductor layer; a third optical symmetric layer disposed on and contacting a surface of the second semiconductor layer away from the substrate, wherein a refractive index of the third optical symmetric layer is in a range from about 1.2 to about 1.5; a metallic layer disposed on and contacting a surface of the third optical symmetric layer away from the substrate; a fourth optical symmetric layer disposed on and contacting a surface of the metallic layer away from the substrate, wherein a refractive index of the fourth optical symmetric layer is in a range from about 1.2 to about 1.5; a first optical symmetric layer disposed on and contacting a surface of the fourth optical symmetric layer away from the substrate, wherein a refractive index difference between the source layer and the first optical symmetric layer is less than or equal to 0.3; and a second optical symmetric layer disposed on a surface of the first semiconductor layer away from the substrate, wherein a refractive difference between the second optical symmetric layer and the substrate is less than or equal to 0.1.