a substrate which has opposing first and second surfaces;

an epitaxial structure which includes a first semiconductor layer, an active layer and a second semiconductor layer that sequentially disposed on said first surface in such order;

a conductive bonding layer which is disposed between said substrate and said epitaxial structure, and which is electrically connected to said second semiconductor layer; and

an electrode contact layer, a metallic reflective layer, a current blocking layer and a transparent conducting layer that are sequentially disposed on said conductive bonding layer opposite to said substrate in such order;

wherein said second semiconductor layer has a light-emitting surface opposite to said active layer, and is formed with a microstructure on said light-emitting surface, said microstructure including a plurality of first protrusions and a plurality of second protrusions, said first protrusion being separately disposed on said light-emitting surface, said second protrusions being disposed on said first protrusions and on said light-emitting surface between any two adjacent ones of said first protrusions;

wherein said transparent conducting layer is located below said first semiconductor layer opposite to said active layer and is electronically connected to said first semiconductor layer; and

wherein said current blocking layer is formed with a plurality of openings, said metallic reflective layer filling said openings to be electronically connected to said transparent conducting layer.