Micro-LED structure and micro-LED chip including same
A micro-LED chip includes multiple micro-LEDs. At least one micro-LED of the multiple micro-LEDs includes: a first type conductive layer; a second type conductive layer stacked on the first type conductive layer; and a light emitting layer formed between the first type conductive layer and the second type conductive layer. The light emitting layer is continuously formed on the whole micro-LED chip, and the multiple micro-LEDs sharing the light emitting layer. The micro-LED chip further includes: a top spacer formed on a top surface of the light emitting layer; a bottom spacer formed on a bottom surface of the light emitting layer; and an isolation structure formed between adjacent micro-LEDs.
1 . A micro-LED chip including multiple micro-LEDs, wherein,
at least one micro-LED of the multiple micro-LEDs comprises:
a first type conductive layer;
a second type conductive layer stacked on the first type conductive layer; and
a light emitting layer formed between the first type conductive layer and the second type conductive layer,
wherein the light emitting layer extends to exterior edges of the micro-LED chip, the multiple micro-LEDs sharing the light emitting layer,
the at least one micro-LED further comprises:
a top spacer formed between the second type conductive layer and the light emitting layer and directly contacting a top surface of the light emitting layer; and
a bottom spacer formed between the first type conduct layer and the light emitting layer and directly contacting a bottom surface of the light emitting layer, wherein an edge of the top spacer is aligned with an edge of the light emitting layer, and an edge of the bottom spacer is aligned with the edge of the light emitting layer; and
the micro-LED chip further comprises:
an isolation structure formed between adjacent micro-LEDs, wherein at least a portion of the isolation structure is formed in the light emitting layer, a bottom surface of the isolation structure is under the light emitting layer and above a bottom surface of the bottom spacer, and a top surface of the isolation structure is above the top spacer and above a top surface of the second type conductive layer.
2 . The micro-LED chip according to claim 1 , wherein a top surface area of the isolation structure is equal to a bottom surface area of the isolation structure.
3 . The micro-LED chip according to claim 1 , wherein a top surface area of the isolation structure is larger than a bottom surface area of the isolation structure.
4 . The micro-LED chip according to claim 1 , wherein a top surface area of the isolation structure is smaller than a bottom surface area of the isolation structure.
5 . The micro-LED chip according to claim 4 , wherein a cross-sectional area of the isolation structure at a bottom of the light emitting layer is larger than the bottom surface area of the isolation structure.
6 . The micro-LED chip according to claim 1 , wherein the isolation structure is made of a light absorption material.
7 . The micro-LED chip according to claim 1 , wherein the isolation structure is made of a reflective material.
8 . The micro-LED chip according to claim 1 , wherein a top area of the first type conductive layer is larger than a bottom area of the first type conductive layer, and a top area of the second type conductive layer is smaller than a bottom area of the second type conductive layer.
9 . The micro-LED chip according to claim 1 , wherein the light emitting layer includes only one pair of quantum well layers, or multiple pairs of quantum well layers.
10 . The micro-LED chip according to claim 1 , wherein a thickness of the top spacer is larger than a thickness of the light emitting layer, and a thickness of the bottom spacer is larger than the thickness of the light emitting layer.
11 . The micro-LED chip according to claim 1 , wherein the at least one micro-LED further comprises a reflective structure formed surrounding the first type conductive layer.
12 . The micro-LED chip according to claim 11 , wherein, in the at least one micro-LED, the reflective structure is attached on a sidewall of the first type conductive layer, and
the at least one micro-LED further comprises a bottom connection structure formed under the first type conductive layer and electrically connected with the first type conductive layer.
13 . The micro-LED chip according to claim 12 , further comprising a substrate under the first type conductive layer, and electrically connected with the bottom connection structure by a connecting pad in the substrate.
14 . The micro-LED chip according to claim 13 , wherein the reflective structure on the sidewall of the first type conductive layer is inclined relative to a surface of the substrate, and an inclined angle of the reflective structure is approximately 30° to approximately 75° relative to the surface of the substrate.
15 . The micro-LED chip according to claim 12 , wherein the reflective structure on the sidewall of the first type conductive layer has a curved surface.
16 . The micro-LED chip according to claim 12 , wherein the reflective structure is attached both on the sidewall and a bottom surface of the first type conductive layer.
17 . The micro-LED chip according to claim 12 , wherein the reflective structure at the sidewall of the first type conductive layer is made of an ODR (omnidirectional reflector) structure or a DBR (distributed bragg reflection) structure.
18 . The micro-LED chip according to claim 11 , wherein, in the at least one micro-LED, the reflective structure is configured to focus light on the second type conductive layer.
19 . The micro-LED chip according to claim 1 , wherein the at least one micro-LED further comprises:
a reflective structure attached on a bottom surface of the first type conductive layer.
20 . The micro-LED chip according to claim 1 , further comprising, in the at least one micro-LED, a microlens formed on the second type conductive layer and on a top surface of the top spacer.