A semiconductor light emitting device including a first conductivity-type semiconductor layer; a second conductivity-type semiconductor layer; an active layer interposed between the first conductivity-type semiconductor layer and the second conductivity-type semiconductor layer, the active layer including at least one quantum well layer and at least one quantum barrier layer that are alternately stacked and form a multiple quantum well structure; at least one border layer in contact with the first conductivity-type semiconductor layer and interposed between the first conductivity-type semiconductor layer and the active layer, the at least one border layer having a band gap energy that decreases in a direction away from the first conductivity-type semiconductor layer; and at least one growth blocking layer interposed between the active layer and the border layer, the at least one growth blocking layer having a band gap energy equal to a band gap energy of the at least one quantum barrier layer.