A light-emitting device includes a substrate having an epitaxial-forming surface and a back surface opposite to the epitaxial-forming surface, the substrate being formed with a recess indented from the back surface, the back surface having a recessed portion that defines the recess, and a planar portion extending outwardly from the recessed portion; an epitaxy layer; a continuous heat-dissipating layer formed on the planar portion and the recessed portion of the back surface of the substrate; and first and second electrodes coupled electrically to the epitaxy layer.