Light emitters using nanotubes and methods of making same. A light emitter includes a nanotube article in electrical communication with a first and a second contact, a substrate having a predefined region with a relatively low thermal conductivity said region in predefined physical relation to said nanotube article; and a stimulus circuit in electrical communication with the first and second contacts. The stimulus circuit provides electrical stimulation sufficient to induce light emission from the nanotube article in the proximity of the predefined region. The predefined region is a channel formed in the substrate or a region of material with relatively low thermal conductivity. The light emitter can be integrated with semiconductor circuits including CMOS circuits. The light emitter can be integrated into optical driver circuits (on- and off-chip drivers) and opto-isolators.