Light-emitting element having multilayered light-emitting layer, and display device including the same

1 . A light-emitting element comprising:

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

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

a light-emitting layer disposed between the first and second semiconductor layers, wherein

the light-emitting element has a rod shape having an aspect ratio in a range of about 1.2:1 to about 100:1,

the light-emitting layer includes:

at least one first material layer; and

at least one second material layer,

the at least one first material layer is a quantum well layer in which electrons and holes recombine and is made of a zinc oxide (ZnO), and

the at least one second material layer is a barrier layer and is made of a gallium nitride (GaN).

2 . The light-emitting element of claim 1 , wherein the light-emitting layer is a multilayer in which a plurality of first material layers and a plurality of second material layers are alternately stacked.

3 . The light-emitting element of claim 1 , wherein a bandgap energy of the at least one first material layer is less than a bandgap energy of the at least one second material layer.

4 . The light-emitting element of claim 1 , wherein

an averaged composition of GaN and ZnO in the light-emitting layer is (GaN) 1-x (ZnO) x , and

x is in a range of about 0.22 to about 0.75.

5 . The light-emitting element of claim 4 , wherein a wavelength of light emitted from the light-emitting layer is in a range of about 450 nm to about 495 nm.

6 . The light-emitting element of claim 1 , wherein

an averaged composition of GaN and ZnO in the light-emitting layer is (GaN) 1-x (ZnO) x , and

x is equal to or less than about 0.22.

7 . The light-emitting element of claim 6 , wherein a wavelength of light emitted from the light-emitting layer is in a range of about 495 nm to about 550 nm.

8 . The light-emitting element of claim 1 , wherein a bandgap energy of the light-emitting layer is in a range of about 2.2 eV to about 2.7 eV.

9 . The light-emitting element of claim 8 , wherein light emitted from the light-emitting layer has a quantum efficiency equal to or greater than about 79%.

10 . The light-emitting element of claim 1 , wherein a rate of lattice mismatch between the at least one first material layer and the at least one second material layer is equal to or less than about 1.8%.

11 . The light-emitting element of claim 1 , wherein the at least one first material layer further includes indium (In).

12 . The light-emitting element of claim 11 , wherein a wavelength of light emitted from the light-emitting layer is in a range of about 550 nm to about 690 nm.

13 . The light-emitting element of claim 11 , wherein a bandgap energy of the light-emitting layer is in a range of about 1.8 eV to about 2.2 eV.

14 . The light-emitting element of claim 11 , wherein an In content of the first material layer is equal to or less than about 10%.

15 . The light-emitting element of claim 1 , further comprising:

a device electrode layer disposed on the second semiconductor layer; and

an insulating film surrounding outer surfaces of each of the first semiconductor layer, the light-emitting layer, and the second semiconductor layer.

16 . An electronic device comprising:

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

a light-emitting element disposed between the first and second electrodes, the light-emitting element having a first end portion and a second end portion;

a first connecting electrode contacting the first end portion of the light-emitting element; and

a second connecting electrode contacting the second end portion of the light-emitting element, wherein

the light-emitting element has a rod shape having an aspect ratio in a range of about 1.2:1 to about 100:1,

the light-emitting element includes:

a first semiconductor layer;

a second semiconductor layer; and

a light-emitting layer, which is disposed between the first semiconductor layer and the second semiconductor layer, and the light-emitting layer includes:

at least one first material layer, which is a quantum well layer in which electrons and holes recombine and is made of a zinc oxide (ZnO); and

at least one second material layer, which is a barrier layer and is made of a gallium nitride (GaN).

17 . The electronic device of claim 16 , wherein

an averaged composition of GaN and ZnO in the light-emitting layer is (GaN) 1-x (ZnO) x , and

x is in a range of about 0.22 to about 0.75.

18 . The electronic device of claim 16 , wherein the at least one first material layer further includes indium (In) in an amount equal to or less than about 10%.

19 . An electronic device comprising:

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

a light-emitting element disposed between the first and second electrodes, the light-emitting element having a first end portion and a second end portion;

a first connecting electrode contacting the first end portion of the light-emitting element; and

a second connecting electrode contacting the second end portion of the light-emitting element, wherein

the light-emitting element includes:

a first semiconductor layer;

a second semiconductor layer; and

a light-emitting layer, which is disposed between the first semiconductor layer and the second semiconductor layer, the light-emitting layer includes:

at least one first material layer, which is a quantum well layer in which electrons and holes recombine and is made of a zinc oxide (ZnO); and

at least one second material layer, which is a barrier layer and is made of a gallium nitride (GaN), and

the at least one first material layer and the at least second material layer are alternately arranged in a direction parallel to one surface of the substrate.