A light-emitting module includes a housing and light-emitting units. The housing includes a bottom board. The light-emitting units are separately disposed on the bottom board and are arranged along a first direction and a second direction which intersects with the first direction to form an array. Each of the light-emitting units includes a first light-emitting element and two second light-emitting elements which respectively have upper surfaces away from the bottom board. The second light-emitting elements are disposed at two opposite sides of the first light-emitting element. A ratio of a length of any one of the second light-emitting elements parallel to the first direction to a length of the first light-emitting element parallel to the first direction ranges from 0.35 to 0.55. A sum of areas of the upper surfaces of the second light-emitting elements is not greater than an area of the upper surface of the first light-emitting element.

A light emitting device includes a light emitting device includes: a first nitride semiconductor layer doped with an n-type dopant and having a first lattice constant; an active layer provided on the first nitride semiconductor layer and having a second lattice constant greater than the first lattice constant, the active layer including a nitride semiconductor material including indium; a stress relaxation layer interposed between the first nitride semiconductor layer and the active layer and having a third lattice constant between the first lattice constant and the second lattice constant, the stress relaxation layer including a nitride semiconductor material including indium; and a second nitride semiconductor layer provide on the active layer and doped with a p-type dopant, wherein the active layer includes: an upper active region provided on an upper surface of the stress relaxation layer, and a side active region provided on a side surface of the stress relaxation layer.