  Heat dissipation in electrically biased semiconducting carbon nanotubes
(CNTs) on single crystal quartz and amorphous SiO2 is examined with temperature
profiles obtained by spatially resolved Raman spectroscopy. Despite the
differences in phonon velocities, thermal conductivity and van der Waals
interactions with CNTs, on average, heat dissipation into single crystal quartz
and amorphous SiO2 is found to be similar. Large temperature gradients and
local hot spots often observed underscore the complexity of CNT temperature
profiles and may be accountable for the similarities observed.
