Semiconductor light-emitting device and light emitting apparatus including the same

A semiconductor light-emitting device, comprising:

• a semiconductor stack which includes an N-type semiconductor layer, a light-emitting layer, and a P-type semiconductor layer, said N-type semiconductor layer, said light-emitting layer and said P-type semiconductor layer being stacked in such an order in a thickness direction,
• wherein said N-type semiconductor layer includes a first layer, a second layer, and a third layer, said first layer being an Alx1Ga1-x1N semiconductor layer that has a first concentration of an n-type impurity greater than or equal to 5×1018 atoms/cm3, said third layer being a superlattice structure that contains Alx3Ga1-x3N, being proximate to said light-emitting layer, having a second concentration of said n-type impurity less than 1 ×1018 atoms/cm3, and having a thickness greater than or equal to 10 nm, said second layer being an Alx2Ga1-x2N semiconductor layer that is disposed between said first layer and said third layer, and having a concentration of said n-type impurity less than said first concentration of said n-type impurity and greater than said second concentration of said n-type impurity.

A semiconductor light-emitting device, comprising:

• a semiconductor stack which includes an N-type semiconductor layer, a light-emitting layer and a P-type semiconductor layer stacked in such an order along a thickness direction, said light-emitting layer emitting light having a wavelength ranging from 340 nm to 425 nm;
• wherein said semiconductor stack has an n-type impurity that has a concentration profile along the thickness direction, said concentration profile corresponding to a region from said N-type semiconductor layer toward said P-type semiconductor layer, and indicating a concentration of said n-type impurity in said region, said concentration of said n-type impurity being less than or equal to 5×1016 atoms/cm3, said region having a thickness greater than or equal to 50 nm and less than 300 nm.