Display device having light emitting diodes with recessed portions between semiconductor layers

1 . A display device comprising:

a board including a wiring electrode; and

a plurality of semiconductor light emitting diodes electrically connected to the wiring electrode;

wherein each of the plurality of semiconductor light emitting diodes includes:

a first conductivity type semiconductor layer;

an active layer on the first conductivity type semiconductor layer; and

a second conductivity type semiconductor layer on the active layer,

wherein the first conductivity type semiconductor layer includes a plurality of recessed portions,

wherein the first conductivity type semiconductor layer includes a plurality of first semiconductor layers and a plurality of second semiconductor layers that are alternately stacked, and

wherein the plurality of recessed portions are between the plurality of first semiconductor layers.

2 . The display device of claim 1 , wherein the plurality of recessed portions are formed in the plurality of second semiconductor layers, and

wherein a number of the plurality of recessed portions formed in each semiconductor light emitting diode is a same as a number of the plurality of second semiconductor layers or an integer multiple of the number of the plurality of second semiconductor layers.

3 . The display device of claim 2 , wherein, for a recessed portion among the plurality of recessed portions, inner walls of the recessed portion is formed of one surface of one first semiconductor layer and a side surface of one second semiconductor layer from among the plurality of first semiconductor layers and the plurality of second semiconductor layers.

4 . The display device of claim 3 , wherein an etching rate for a predetermined solution of a material constituting the second semiconductor layer is faster than an etching rate for the predetermined solution of a material constituting the active layer, the first semiconductor layer, and the second conductivity type semiconductor layer.

5 . The display device of claim 4 , wherein the second semiconductor layer is formed of AlInP,

wherein the active layer, the first semiconductor layer, and the second conductivity type semiconductor layer are formed of AlGaInP, and

wherein the first semiconductor layer and the second semiconductor layer are doped with a first dopant, and the second conductive type semiconductor layer is doped with a second dopant.

6 . The display device of claim 3 , wherein each of the plurality of semiconductor light emitting diodes includes:

a first barrier layer between the first conductivity type semiconductor layer and the active layer; and

a second barrier layer between the active layer and the second conductivity type semiconductor layer.

7 . The display device of claim 6 , wherein each of the plurality of semiconductor light emitting diodes includes:

a first recessed portion between the first conductivity type semiconductor layer and the active layer, and

a second recessed portion between the active layer and the second conductivity type semiconductor layer.

8 . The display device of claim 7 , wherein the first recessed portion is in the first barrier layer, and the second recessed portion is in the second barrier layer.

9 . The display device of claim 8 , wherein a lateral length of the active layer is longer than a lateral length of the first barrier layer and a lateral length of the second barrier layer.

10 . The display device of claim 1 , wherein the first conductivity type semiconductor layer includes a first semiconductor layer of the plurality of first semiconductor layers and a second semiconductor layer of the plurality of second semiconductor layers, and

wherein among Al, Ga, In and P, the second semiconductor layer includes Al, In and P but not Ga, and the first semiconductor layer includes Al, Ga, In and P.

11 . A display device comprising:

a board including a wiring electrode; and

a plurality of semiconductor light emitting diodes electrically connected to the wiring electrode,

wherein each of the plurality of semiconductor light emitting diodes includes:

a first conductivity type semiconductor layer;

a barrier layer on the first conductivity type semiconductor layer;

an active layer on the barrier layer; and

a second conductivity type semiconductor layer on the active layer,

wherein at least one of the barrier layer and the first conductivity type semiconductor layer includes a plurality of recessed portions in a plane direction of the at least one of the barrier layer and the first conductivity type semiconductor layer,

wherein the first conductivity type semiconductor layer includes a plurality of first semiconductor layers and a plurality of second semiconductor layers that are alternately stacked, and

wherein the plurality of recessed portions are between the plurality of first semiconductor layers.

12 . The display device of claim 11 , wherein among Al, Ga, In and P, each of the first conductivity type semiconductor layer, the barrier layer, the active layer, and second conductivity type semiconductor layer includes at least Al, In and P, and only the least one of the barrier layer and the first conductivity type semiconductor layer includes Ga.

13 . The display device of claim 12 ,

wherein only the second semiconductor layers include recessed portions from among the first semiconductor layers and the second semiconductor layers.

14 . The display device of claim 11 , wherein the barrier layer also includes a recessed portion.