Light emitting diode

A light emitting diode, comprising:

• a substrate;
• a first semiconductor layer comprising a first surface contacting the substrate and a second surface opposite to the first surface;
• an active layer stacked on the second surface of the first semiconductor layer;
• a second semiconductor layer stacked on the active layer and comprising a light emitting surface away from the active layer;
• a first electrode electrically connected with the first semiconductor layer;
• a second electrode electrically connected with the second semiconductor layer;
• wherein a plurality of first three-dimensional nano-structures are located on the second surface of the first semiconductor layer, a plurality of second three-dimensional nano-structures are located on a surface of the substrate contacting the first semiconductor layer, wherein each of the plurality of first three-dimensional nano-structures and the plurality of second three-dimensional nano-structures comprises a first peak and a second peak, a first groove is defined between the first peak and the second peak, a second groove is defined between adjacent two of the first three-dimensional nano-structures and adjacent two of the second three-dimensional nano-structures, and a depth of the first groove is less than a depth of the second groove.