Light emitting diode and light emitting device using the same

A light emitting diode comprising:

• an semiconductor structure having a first surface and a second surface, said semiconductor structure including an N-type semiconductor layer, an active layer, and a P-type semiconductor layer that includes a P-type contact layer, and a P-type base layer located between said P-type contact layer and said active layer, said active layer being located between said N-type semiconductor layer and said P-type semiconductor layer;
• a first electrode located on said second surface of said semiconductor structure, and electrically connected to said N-type semiconductor layer;
• and a second electrode located on said second surface of said semiconductor structure, and electrically connected to said P-type semiconductor layer;
• wherein a P-type dopant concentration in said P-type contact layer gradually decreases along a direction from said first surface towards said second surface, wherein:
• said P-type semiconductor layer further includes a P-type hole injection layer located between said P-type base layer and said P-type contact layer;
• and a P-type dopant concentration in said P-type hole injection layer gradually increases along a direction from the first surface towards said second surface.