Light-emitting element comprising a reflective structure with high efficiency

摘要

A light-emitting element, comprises: a substrate; a light-emitting semiconductor stack over the substrate and comprising an active layer; and a Distributed Bragg reflective unit under the substrate comprising a first Distributed Bragg reflective structure under the substrate and comprising a first number of pairs of alternately stacked first sub-layers and second sub-layers, and a second Distributed Bragg reflective structure under the first Distributed Bragg reflective structure and comprising a second number of pairs of alternately stacked third sub-layers and fourth sub-layers, wherein the first number is different from the second number.

主权项

1. A light-emitting element, comprising:
a substrate, comprising a first portion and a second portion surrounding the first portion, wherein the second portion has a vertical thickness smaller than a vertical thickness of the first portion, and the first portion comprises a textured surface comprising alternate concave structures and convex structures; a light-emitting semiconductor stack over the substrate and comprising an active layer; and a Distributed Bragg reflective unit under the substrate and comprising a first Distributed Bragg reflective structure conformably formed on the textured surface of the substrate and comprising a first number of pairs of alternately stacked first sub-layers and second sub-layers, and a second Distributed Bragg reflective structure conformably formed on the first Distributed Bragg reflective structure and comprising a second number of pairs of alternately stacked third sub-layers and fourth sub-layers, wherein the first number is different from the second number.