A light-emitting device includes a first conductive type semiconductor layer, a second conductive type semiconductor layer, and an active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer and having a plurality of V-pits. The light-emitting device further includes a layer-quality improvement layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer and having a plurality of V-pits with substantially same size and shape as the plurality of V-pits of the active layer, wherein layer-quality improvement layer is a group III-V semiconductor layer including Al or In. Due to the improved layer quality, the luminescent quality of the light-emitting device is improved.