Light emitting device, display apparatus, and manufacturing method thereof
A light emitting device includes a light emitting device includes: a first nitride semiconductor layer doped with an n-type dopant and having a first lattice constant; an active layer provided on the first nitride semiconductor layer and having a second lattice constant greater than the first lattice constant, the active layer including a nitride semiconductor material including indium; a stress relaxation layer interposed between the first nitride semiconductor layer and the active layer and having a third lattice constant between the first lattice constant and the second lattice constant, the stress relaxation layer including a nitride semiconductor material including indium; and a second nitride semiconductor layer provide on the active layer and doped with a p-type dopant, wherein the active layer includes: an upper active region provided on an upper surface of the stress relaxation layer, and a side active region provided on a side surface of the stress relaxation layer.
1 . A light emitting device comprising:
a first nitride semiconductor layer doped with an n-type dopant and having a first lattice constant;
an active layer provided on the first nitride semiconductor layer and having a second lattice constant greater than the first lattice constant, the active layer comprising a nitride semiconductor material comprising indium;
a stress relaxation layer interposed between the first nitride semiconductor layer and the active layer and having a third lattice constant between the first lattice constant and the second lattice constant, the stress relaxation layer comprising a nitride semiconductor material comprising indium; and
a second nitride semiconductor layer provided on the active layer and doped with a p-type dopant,
wherein the active layer comprises:
an upper active region provided on an upper surface of the stress relaxation layer, and
a side active region comprising a side surface directly contacting a side surface of the stress relaxation layer and a side surface of the first nitride semiconductor layer,
wherein the light emitting device has a width in a first direction that is less than a length thereof in a second direction perpendicular to the first direction, and
wherein the side surface of the stress relaxation layer, the side surface of the first nitride semiconductor layer and the side surface of the side active region are aligned in the second direction.
2 . The light emitting device of claim 1 , wherein, in the stress relaxation layer, a fourth lattice constant of a region facing the active layer is greater than a fifth lattice constant of a region facing the first nitride semiconductor layer, and
wherein a difference between the fourth lattice constant and the fifth lattice constant in the stress relaxation layer is about 1% or more of the first lattice constant.
3 . The light emitting device of claim 1 , wherein, in the active layer, a thickness of the side active region in the first direction is less than a thickness of the upper active region in the second direction.
4 . The light emitting device of claim 1 , further comprising a first passivation layer provided on the side surface of the first nitride semiconductor layer,
wherein the side active region contacts the first passivation layer.
5 . The light emitting device of claim 1 , wherein the stress relaxation layer comprises InGaN, and
wherein the active layer comprises InGaN.
6 . The light emitting device of claim 1 , wherein an indium content of the stress relaxation layer is less than an indium content of the active layer.
7 . The light emitting device of claim 1 , wherein the active layer comprises an indium content of about 20% or more such that the active layer is configured to emit long-wavelength light.
8 . The light emitting device of claim 1 , wherein a width of the active layer is about 10 μm or less.
9 . The light emitting device of claim 1 , wherein the second nitride semiconductor layer is provided on the upper active region.
10 . The light emitting device of claim 1 , wherein the active layer comprises a plurality of active layers spaced apart from each other.
11 . The light emitting device of claim 10 , wherein the plurality of active layers have different widths.
12 . The light emitting device of claim 10 , wherein the second nitride semiconductor layer connects the plurality of active layers to each other.
13 . The light emitting device of claim 1 , wherein the stress relaxation layer comprises a superlattice layer comprising a plurality of thin film layers having a thickness of about 10 nm or less.
14 . The light emitting device of claim 1 , wherein the stress relaxation layer comprises a single layer having an indium content of about 20% or less and a thickness of about 10 nm or less.
15 . A display apparatus comprising:
a light emitting device comprising:
a first nitride semiconductor layer doped with an n-type dopant and having a first lattice constant;
an active layer provided on the first nitride semiconductor layer and having a second lattice constant greater than the first lattice constant, the active layer comprising a nitride semiconductor material comprising indium;
a stress relaxation layer interposed between the first nitride semiconductor layer and the active layer and having a third lattice constant between the first lattice constant and the second lattice constant, the stress relaxation layer comprising a nitride semiconductor material comprising indium; and
a second nitride semiconductor layer provided on the active layer and doped with a p-type dopant,
wherein the active layer comprises:
an upper active region provided on an upper surface of the stress relaxation layer, and
a side active region comprising a side surface directly contacting a side surface of the stress relaxation layer and a side surface of the first nitride semiconductor layer,
wherein the light emitting device has a width in a first direction that is less than a length thereof in a second direction perpendicular to the first direction, and
wherein the side surface of the stress relaxation layer, the side surface of the first nitride semiconductor layer and the side surface of the side active region are aligned in the second direction.