Light emitting device having a stacked structure

A light emitting device comprising:

• a first light emitting part including a first n-type semiconductor layer, a first active layer, and a first p-type semiconductor layer;
• a second light emitting part disposed on a first surface of the first light emitting part, and including a second n-type semiconductor layer, a second active layer, and a second p-type semiconductor layer, the second n-type semiconductor layer having a first surface and a second surface opposing the first surface;
• a third light emitting part disposed on a first surface of the second light emitting part, and including a third n-type semiconductor layer, a third active layer, and a third p-type semiconductor layer;
• a first contact structure contacting the first surface of the second n-type semiconductor layer;
• and
• a second contact structure contacting the second surface of the second n-type semiconductor layer, wherein:
• the first contact structure extends into the first light emitting part to electrically contact the first n-type semiconductor layer;
• and
• the second contact structure extends into the second light emitting part to electrically contact the third n-type semiconductor layer.