Near UV light emitting device

1. A light emitting device, comprising:

an n-type contact layer comprising a GaN layer;

a p-type contact layer comprising a GaN layer;

an active area comprising barrier layers and well layers that form a multi-quantum well structure disposed between the n-type contact layer and the p-type contact layer, the barrier layers comprising Al, the active area configured to emit near ultraviolet light at wavelengths of 375 nm to 390 nm;

a superlattice layer disposed between the n-type contact layer and the active area; and

an electron implantation layer disposed between the superlattice layer and the active area, the electron implantation layer comprising a higher n-type impurity doping density than the superlattice layer,

wherein a first one of the barrier layers is disposed closest to the n-type contact layer, comprises 10% to 20% more Al than the other barrier layers, and has at least a 0.5 eV wider band gap than the other barrier layers, and

wherein the active layer adjoins the electron implantation layer.

2. The light emitting device of claim 1 , wherein the barrier layers except for the first barrier layer comprise AlInGaN comprising 15% to 25% of Al and 1% or less of In.

3. The light emitting device of claim 2 , wherein the first barrier layer comprises AlInGaN comprising 30% to 40% of Al and 1% or less of In.

4. The light emitting device of claim 1 , wherein the p-type contact layer comprises:

a first high-density doping layer;

a second high-density doping layer; and

a low-density doping layer disposed between the first high-density doping layer and the second high-density doping layer.

5. The light emitting device of claim 4 , wherein the low-density doping layer is thicker than the first and second high-density doping layers.

6. The light emitting device of claim 1 , wherein the n-type contact layer comprises:

a first GaN layer;

a second GaN layer; and

an intermediate layer comprising a multilayer structure and disposed between the first and second GaN layers.

7. The light emitting device of claim 6 , wherein the intermediate layer comprises alternately stacked AlInN and GaN layers.

8. The light emitting device of claim 1 , wherein the superlattice layer comprises a sequentially stacked InGaN/InGaN structure, and the electron implantation layer comprises GaN or InGaN.

9. The light emitting device of claim 1 , further comprising an undoped GaN layer disposed between the n-type contact layer and the superlattice layer.

10. The light emitting device of claim 9 , further comprising:

a low-density GaN layer disposed between the undoped GaN layer and the superlattice layer, the low-density GaN layer being doped with an n-type impurity at a lower density than the n-type contact layer; and

a high-density GaN layer disposed between the low-density GaN layer and the superlattice layer, the high-density GaN layer being doped with an n-type impurity at a higher density than the low-density GaN layer.