Light emitting device, light emitting device package, method of manufacturing light emitting device and lighting system

A light emitting device comprising:

• a first conductive semiconductor layer;
• an active layer adjacent to the first conductive semiconductor layer, the active layer including a first quantum well layer, a second quantum well layer and a barrier layer between the first quantum well layer and the second quantum well layer;
• and
• a second conductive semiconductor layer adjacent to the active layer,
• wherein the first quantum well layer includes a first plurality of sub-barrier layers and a first plurality of sub-quantum well layers, and the second quantum well layer includes a second plurality of sub-barrier layers and a second plurality of sub-quantum well layers, and
• wherein a bandgap of the first plurality of sub-barrier layers is different than a bandgap of the second plurality of sub-barrier layers,
• wherein the bandgap of the second plurality of sub-barrier layers is lower than a bandgap of the barrier layer, and
• wherein a bandgap of the second plurality of sub-quantum well layers is lower than the bandgap of the second plurality of sub-barrier layers.