NANOROD LIGHT-EMITTING DEVICE, METHOD OF MANUFACTURING THE SAME, AND DISPLAY APPARATUS INCLUDING THE SAME
Provided is a nanorod light-emitting device including a support layer, a first-type semiconductor nanocore protruding from an upper surface of the support layer and including a semiconductor material doped as a first conductivity type, a mask layer on an upper surface of the support layer and extending to a first height of the first-type semiconductor nanocore in a vertical direction and adjacent to a surface of the first-type semiconductor nanocore, a light-emitting layer having a multi-quantum well structure adjacent to a portion of the first-type semiconductor nanocore above the first height in the vertical direction, and a second-type semiconductor layer adjacent to a surface of the light-emitting layer and including a semiconductor material doped as a second conductivity type.
1 . A nanorod light-emitting device comprising:
a support layer;
a first-type semiconductor nanocore protruding from an upper surface of the support layer and comprising a semiconductor material doped as a first conductivity type;
a mask layer on an upper surface of the support layer and extending to a first height of the first-type semiconductor nanocore in a vertical direction and adjacent to a surface of the first-type semiconductor nanocore;
a light-emitting layer having a multi-quantum well structure adjacent to a portion of the first-type semiconductor nanocore above the first height in the vertical direction; and
a second-type semiconductor layer adjacent to a surface of the light-emitting layer and comprising a semiconductor material doped as a second conductivity type.
2 . The nanorod light-emitting device of claim 1 , wherein the support layer and the first-type semiconductor nanocore are integrally formed.
3 . The nanorod light-emitting device of claim 1 , wherein a first end of the mask layer has a tapered shape.
4 . The nanorod light-emitting device of claim 1 , wherein the first height is greater than or equal to 5% of a height of the first-type semiconductor nanocore.
5 . The nanorod light-emitting device of claim 1 , further comprising an insulating layer extending from a lower surface of the mask layer to a second height of the first-type semiconductor nanocore in the vertical direction and adjacent to the mask layer and the light-emitting layer.
6 . The nanorod light-emitting device of claim 5 , wherein the second height is greater than the first height.
7 . The nanorod light-emitting device of claim 1 , wherein the first-type semiconductor nanocore comprises:
a first portion having a uniform cross-sectional area in a horizontal direction perpendicular to the vertical direction of the first-type semiconductor nanocore; and
a second portion having a cross-sectional area in the horizontal direction decreasing in the vertical direction away from the support layer.
8 . The nanorod light-emitting device of claim 7 , wherein a region of the light-emitting layer and a region of the second-type semiconductor layer on the second portion is a light emission disabling region.
9 . The nanorod light-emitting device of claim 1 , further comprising a hard mask layer on top of the first-type semiconductor nanocore.
10 . The nanorod light-emitting device of claim 1 , further comprising a super lattice layer between the first-type semiconductor nanocore and the light-emitting layer.
11 . The nanorod light-emitting device of claim 1 , further comprising an electron blocking layer between the light-emitting layer and the second-type semiconductor layer.
12 . The nanorod light-emitting device of claim 1 , wherein the first-type semiconductor nanocore, the light-emitting layer, and the second-type semiconductor layer comprise a Group III-V nitride semiconductor material.
13 . The nanorod light-emitting device of claim 1 , wherein the nanorod light-emitting device is configured to emit red light and an internal quantum efficiency of the nanorod light-emitting device is greater than 20%.
14 . A display apparatus comprising:
a plurality of pixel electrodes;
a common electrode corresponding to the plurality of pixel electrodes; and
a plurality of nanorod light-emitting devices connected between each pixel electrode of the plurality of pixel electrodes and the common electrode,
wherein each nanorod light-emitting device of the plurality of nanorod light-emitting devices comprises:
a support layer;
a first-type semiconductor nanocore protruding from an upper surface of the support layer and comprising a semiconductor material doped as a first conductivity type;
a mask layer on an upper surface of the support layer and extending to a first height of the first-type semiconductor nanocore in a vertical direction and adjacent to a surface of the first-type semiconductor nanocore;
a light-emitting layer having a multi-quantum well structure adjacent to a portion of the first-type semiconductor nanocore above the first height in the vertical direction; and
a second-type semiconductor layer adjacent to a surface of the light-emitting layer and comprising a semiconductor material doped as a second conductivity type.
15 . A method of manufacturing a nanorod light-emitting device, the method comprising:
forming a first-type semiconductor nanocore protruding from a support layer in a first direction;
forming a mask layer adjacent to lower sides of the first-type semiconductor nanocore; and
growing a light-emitting structure layer from a surface of the first-type semiconductor nanocore in a direction different from the first direction.
16 . The method of claim 15 , wherein the forming of the first-type semiconductor nanocore comprises wet etching a semiconductor substrate.
17 . The method of claim 16 , further comprising, after forming a hard mask layer on the semiconductor substrate, patterning the semiconductor substrate and the hard mask layer together.
18 . The method of claim 15 , wherein the growing of the light-emitting structure layer comprises sequentially forming a super lattice layer, a light-emitting layer, an electron blocking layer, and a second-type semiconductor layer.
19 . The method of claim 18 , further comprising, after the growing of the light-emitting structure layer, disabling light emission of the light-emitting structure layer formed on a semi-polar surface on a top of the first-type semiconductor nanocore, among the light-emitting structure layer.
20 . The method of claim 15 , further comprising, after growing the light-emitting structure layer, forming an insulating layer adjacent to an end of the mask layer and the light-emitting structure layer.