Light-emitting element, display device including the same, and semiconductor structure

1 . A light-emitting element comprising:

a first semiconductor layer doped with an n-type dopant;

a second semiconductor layer doped with a p-type dopant;

a light emitting layer disposed between the first semiconductor layer and the second semiconductor layer; and

an insulating film that surrounds the first semiconductor layer, the second semiconductor layer, and the light emitting layer, wherein

an index of doping concentration of the first semiconductor layer is expressed by Equation 1 such that the index of doping concentration of the first semiconductor layer is defined based on a distance from a position of an interface between the first semiconductor layer and the light emitting layer and an end surface of the first semiconductor layer which is opposite the interface between the first semiconductor layer and the light emitting layer, and is equal to or greater than 2.5*10 11 atoms/cm:

IDC (Index of doping concentration)=∫ l0 l n ( x ) xdx   [Equation 1]

wherein in Equation 1,

l 0 is the position of an interface between a semiconductor layer and the light emitting layer,

l is the position of an end surface of the semiconductor layer which is opposite the interface with the light emitting layer,

x is a distance from l 0 to l, and

n(x) is the doping concentration of a dopant according to an x value of the semiconductor layer,

wherein the first semiconductor layer comprises:

a first doped region that contacts the light emitting layer,

a second doped region that contacts the first doped region, and

a third doped region that contacts the second doped region,

wherein the first doped region has a length in a range of about 1,800 nm to about 2,500 nm,

wherein the second doped region has a length in a range of about 500 nm to about 1,200 nm,

wherein the third doped region has a length in a range of about 1,500 nm to about 2,200 nm,

wherein a doping concentration of the n-type dopant of the first doped region is greater than a doping concentration of the n-type dopant of the second doped region,

wherein the doping concentration of the n-type dopant of the second doped region is greater than a doping concentration of the n-type dopant of the third doped region,

wherein doping concentrations of the n-type dopant within the same doped region are the same regardless of position within the same doped region, and

wherein each of the doping concentrations of the n-type dopant of the first to third doped region is equal to or greater than 1*10 18 atoms/cm 3 .

2 . The light-emitting element of claim 1 , wherein the index of doping concentration of the first semiconductor layer is equal to 4*10 11 atoms/cm.

3 . A display device comprising:

a first electrode and a second electrode disposed on a substrate and spaced apart from each other;

a first insulating layer disposed on the first electrode and the second electrode;

light-emitting elements disposed on the first insulating layer and disposed on the first electrode and the second electrode;

a first connection electrode that contacts an end of each of the light-emitting elements; and

a second connection electrode that contacts another end of each of the light-emitting elements, wherein

each of the light-emitting elements comprises:

a first semiconductor layer doped with an n-type dopant;

a second semiconductor layer doped with a p-type dopant;

a light emitting layer disposed between the first semiconductor layer and the second semiconductor layer; and

an insulating film that surrounds the first semiconductor layer, the second semiconductor layer, and the light emitting layer,

an index of doping concentration of the first semiconductor layer is expressed by Equation 1 such that the index of doping concentration of the first semiconductor layer is defined based on a distance from a position of an interface between the first semiconductor layer and the light emitting layer and an end surface of the first semiconductor layer which is opposite the interface between the first semiconductor layer and the light emitting layer, and is equal to or greater than 2.5*10 11 atoms/cm, and

a number of light-emitting elements include first ends at which the first semiconductor layer is disposed and second ends opposite to the first ends, wherein the first ends contact the second connection electrode and the second ends contact the first connection electrode, and

a proportion of the number of light-emitting elements among the light-emitting elements is equal to or greater than 60%:

IDC (Index of doping concentration)=∫ l0 l n ( x ) xdx   [Equation 1]

wherein in Equation 1,

l 0 is the position of an interface between a semiconductor layer and the light emitting layer,

l is the position of an end surface of the semiconductor layer which is opposite the interface with the light emitting layer,

x is a distance from l 0 to l, and

n(x) is the doping concentration of a dopant according to an x value of the semiconductor layer,

wherein the first semiconductor layer comprises:

a first doped region that contacts the light emitting layer,

a second doped region that contacts the first doped region, and

a third doped region that contacts the second doped region,

wherein the first doped region has a length in a range of about 1,800 nm to about 2,500 nm,

wherein the second doped region has a length in a range of about 500 nm to about 1,200 nm,

wherein the third doped region has a length in a range of about 1,500 nm to about 2,200 nm,

wherein a doping concentration of the n-type dopant of the first doped region is greater than a doping concentration of the n-type dopant of the second doped region,

wherein the doping concentration of the n-type dopant of the second doped region is greater than a doping concentration of the n-type dopant of the third doped region,

wherein doping concentrations of the n-type dopant within same doped region are same regardless of position within the same doped region, and

wherein each of the doping concentrations of the n-type dopant of the first to third doped region is equal to or greater than 1*10 18 atoms/cm 3 .

4 . The display device of claim 3 , wherein

the index of doping concentration of the first semiconductor layer in each of the light-emitting elements is equal to or greater than 4*10 11 atoms/cm,

a number of the light-emitting elements include first ends at which the first semiconductor layer is disposed and second ends opposite to the first ends, wherein the first ends contact the second connection electrode and the second ends contact the first connection electrode, and

a proportion of the number of light-emitting elements among the light-emitting elements is equal to or greater than 80%.

5 . A semiconductor structure comprising:

a first semiconductor layer doped with an n-type dopant;

a second semiconductor layer doped with a p-type dopant;

a light emitting layer disposed between the first semiconductor layer and the second semiconductor layer; and

an insulating film that surrounds the first semiconductor layer, the second semiconductor layer, and the light emitting layer,

wherein the first semiconductor layer comprises:

a first doped region that contacts the light emitting layer,

a second doped region that contacts the first doped region, and

a third doped region that contacts the second doped region,

wherein the first doped region has a length in a range of about 1,800 nm to about 2,500 nm,

wherein the second doped region has a length in a range of about 500 nm to about 1,200 nm,

wherein the third doped region has a length in a range of about 1,500 nm to about 2,200 nm,

wherein a doping concentration of the n-type dopant of the first doped region is greater than a doping concentration of the n-type dopant of the second doped region,

wherein the doping concentration of the n-type dopant of the second doped region is greater than a doping concentration of the n-type dopant of the third doped region,

wherein doping concentrations of the n-type dopant within same doped region are same regardless of position within the same doped region, and

wherein each of the doping concentrations of the n-type dopant of the first to third doped region is equal to or greater than 1*10 18 atoms/cm 3 .

6 . The semiconductor structure of claim 5 , wherein the doping concentration of the n-type dopant of the first semiconductor layer is equal to or greater than 6*10 18 atoms/cm 3 .

7 . The semiconductor structure of claim 5 , wherein

the doping concentration of the n-type dopant of the first doped region is equal to or greater than 6*10 18 atoms/cm 3 , and

the doping concentration of the n-type dopant of each of the second doped region and the third doped region is equal to or less than 6*10 18 atoms/cm 3 .

8 . The semiconductor structure of claim 5 , wherein

the doping concentration of the n-type dopant of each of the first doped region and the second doped region is equal to or less than 6*10 18 atoms/cm 3 , and

the doping concentration of the n-type dopant of the third doped region is equal to or greater than 6*10 18 atoms/cm 3 .

9 . The semiconductor structure of claim 5 , wherein

the doping concentration of the n-type dopant of each of the first doped region and the third doped region is equal to or greater than 6*10 18 atoms/cm 3 , and

the doping concentration of the n-type dopant of the second doped region is equal to or less than 6*10 18 atoms/cm 3 .