MICRO LED AND MICRO LED DISPLAY PANEL
A micro LED includes a bonding layer, a P-N structure provided on the bonding layer, wherein the P-N structure comprises a P type semiconductor layer, an N type semiconductor layer and a light emitting layer formed between the P type semiconductor layer and the N type semiconductor layer; a top conductive layer formed on the P-N structure; and a doped P type contact layer, wherein if the P-N structure is a P-side up structure, a doped P type contact layer is provided between the N type semiconductor layer and the bonding layer, or if the P-N structure is an N-side up structure, the doped P type layer is provided between the N type semiconductor layer and the top conductive layer.
1 . A micro LED comprising:
a bonding layer;
a P-N structure formed the bonding layer, wherein the P-N structure comprises a P type semiconductor layer, an N type semiconductor layer, and a light emitting layer formed between the P type semiconductor layer and the N type semiconductor layer;
a top conductive layer formed on the P-N structure; and
a doped P type contact layer, wherein if the P-N structure is a P-side up structure, the doped P type contact layer is provided between the N type semiconductor layer and the bonding layer, or
if the P-N structure is an N-side up structure, the doped P type contact layer is provided between the N type semiconductor layer and the top conductive layer.
2 . The micro LED according to claim 1 , wherein the N type semiconductor layer comprises an N type cladding layer and a doped N type contact layer, if the P-N structure is the P-side up structure, the N type cladding layer is formed on the doped N type contact layer and the doped P type contact layer is provided between the doped N type contact layer and the bonding layer, and
if the P-N structure is the N-side up structure, the doped N type contact layer is formed on the N type cladding layer and the doped P type contact layer is provided between the doped N type contact layer and the top conductive layer.
3 . The micro LED according to claim 2 , wherein materials of the doped N type contact layer and the doped P type contact layer are, respectively n-GaAs and p-GaAs, or n-AlInP and p-AlInP, or n-(Al)(In)(Ga)P and p-(Al)(In)(Ga)P.
4 . The micro LED according to claim 1 , wherein an inclined angle of a sidewall of the P-N structure is greater than 85 degrees.
5 . The micro LED according to claim 4 , wherein the sidewall of the P-N structure is vertical.
6 . The micro LED according to claim 1 , wherein the P-N structure has the P-side up structure, and the N type cladding layer comprises a distributed Bragg reflection (DBR) structure.
7 . The micro LED according to claim 6 , wherein the DBR structure comprises a plurality of first layers and a plurality of second layers, the plurality of first layers and the plurality of second layers being alternately layered.
8 . The micro LED according to claim 7 , wherein materials of the plurality of first layers and the plurality of second layers are, respectively, AlInP and AlGaInP, or AlGaAs and AlAs.
9 . The micro LED according to claim 1 , wherein the bonding layer further comprises;
a metal bonding layer; and
a transparent bonding layer formed on the metal bonding layer.
10 . The micro LED according to claim 9 , wherein the transparent bonding layer comprises a plurality of sputtered transparent bonding layers and a plurality of porous transparent bonding layers, the plurality of sputtered transparent bonding layers and the plurality of porous transparent bonding layers being alternately layered.
11 . The micro LED according to claim 9 , wherein a thickness of the transparent bonding layer is one fourth of a wavelength of light emitted by the light emitting layer.
12 . The micro LED according to claim 9 , wherein the bonding layer further comprises:
a dielectric distributed Bragg reflection (DBR) layer between the transparent bonding layer and the metal bonding layer; and
a side conductive structure provided on a side of the DBR layer for connecting the transparent bonding layer with the metal bonding layer.
13 . A micro LED display panel comprising:
an integrated circuit (IC) backplane comprising a bottom pad array, the bottom pad array comprising a plurality of conductive bottom pads; and
a micro LED array formed on the IC backplane, the micro LED array comprising a plurality of micro LEDs;
wherein one micro LED of the plurality of micro LEDs is electrically connected with one bottom pad of the plurality of conductive bottom pads; and the micro LED comprises:
a bonding layer;
a P-N structure formed the bonding layer, wherein the P-N structure comprises a P type semiconductor layer, an N type semiconductor layer, and a light emitting layer formed between the P type semiconductor layer and the N type semiconductor layer;
a top conductive layer formed on the P-N structure; and
a doped P type contact layer, wherein if the P-N structure is a P-side up structure, the doped P type contact layer is provided between the N type semiconductor layer and the bonding layer, or
if the P-N structure is an N-side up structure, the doped P type contact layer is provided between the N type semiconductor layer and the top conductive layer.
14 . The micro LED display panel according to claim 13 , wherein respective top conductive layers of the plurality of micro LEDs are interconnected.
15 . The micro LED display panel according to claim 14 , wherein the IC backplane further comprises a top connected pad, and the respective top conductive layers are connected with the top connected pad of the IC backplane.