Light emitting element and display device using light emitting element

A display device comprising:

• a circuit board comprising a plurality of driving circuits;
• and
• a pixel array comprising a plurality of light emitting elements on the circuit board,
• wherein a light emitting element of the plurality of light emitting elements comprises:
• a light emitting stack comprising an active layer between an N-type nitride semiconductor layer and a P-type nitride semiconductor layer;
• a first electrode connected to the N-type nitride semiconductor layer;
• and
• a second electrode connected to the P-type nitride semiconductor layer,
• wherein the plurality of light emitting elements are electrically connected to the plurality of driving circuits, respectively,
• wherein the P-type nitride semiconductor layer has a first surface, adjacent to the active layer, and a second surface, opposite to the active layer, and comprises AlxInyGazN (0≤x<1, 0≤y<1, 0<z≤1), wherein a bandgap of the p-type nitride semiconductor layer does not increase in a stacking direction from the second surface to the first surface, and
• wherein the N-type nitride semiconductor layer comprises a superlattice layer and an electron retardation layer.

A pixel array comprising:

• a substrate;
• and
• a plurality of light emitting elements on the substrate,
• wherein a first light emitting elements, among the plurality of light emitting elements, comprises:
• a light emitting stack comprising an active layer between an N-type nitride semiconductor layer and a P-type nitride semiconductor layer, the light emitting stack having a width of 5 nm or more and 200 μm or less;
• a first electrode connected to the N-type nitride semiconductor layer;
• and
• a second electrode connected to the P-type nitride semiconductor layer,
• wherein the P-type nitride semiconductor layer has a first surface, adjacent to the active layer, and a second surface, opposite to the first surface, and comprises AlxInyGazN (0≤x<1, 0≤y<1, 0<z≤1), wherein a bandgap of the p-type nitride semiconductor layer does not increase in a stacking direction from the second surface to the first surface, and
• wherein the N-type nitride semiconductor layer comprises a superlattice layer and an electron retardation layer.