A method for production of an optoelectronic device includes fabricating a plurality of vertical emitters on a semiconductor substrate. Respective top surfaces of the emitters are bonded to a heat sink, after which the semiconductor substrate is removed below respective bottom surfaces of the emitters. Both anode and cathode contacts are attached to the bottom surfaces so as to drive the emitters to emit light from the bottom surfaces. In another embodiment, the upper surface of a semiconductor substrate is bonded to a carrier substrate having through-holes that are aligned with respective top surfaces of the emitters, after which the semiconductor substrate is removed below respective bottom surfaces of the emitters, and the respective bottom surfaces of the emitters are bonded to a heat sink.