Provided is a high-efficiency light emitting diode (LED) that includes: a support substrate; a semiconductor stack positioned on the support substrate, the semiconductor stack including a p-type compound semiconductor layer, an active layer, and an n-type compound semiconductor layer; a first electrode positioned between the support substrate and the semiconductor stack and in ohmic contact with the semiconductor stack; a first bonding pad positioned on a portion of the first electrode that is exposed outside of the semiconductor stack; and a second electrode positioned on the semiconductor stack. Protrusions are formed on exposed surfaces of the semiconductor stack. In addition, the second electrode may be positioned between the first electrode and the support substrate and contacted with the n-type compound semiconductor layer through openings of the semiconductor stack.