a base part;

a plurality of assembly electrodes extending in a first direction and disposed at predetermined intervals on the base part;

a dielectric layer stacked on the base part to cover the plurality of assembly electrodes;

a barrier wall portion stacked on the dielectric layer to define a cell overlapping at least a portion of the plurality of assembly electrodes along the first direction of the plurality of assembly electrodes; and

a plurality of semiconductor light emitting devices disposed in the cell,

wherein the plurality of semiconductor light emitting devices comprise a magnetic layer extending in a longitudinal direction vertical to the first direction,

wherein the plurality of semiconductor light emitting devices respectively comprise a light emitting structure,

wherein the light emitting structure comprises a recessed portion intersecting a center portion of the light emitting structure, and

wherein the magnetic layer is disposed in the recessed portion of the light emitting structure.