Quantitative Thermometry of Nanoscale Hot Spots

Abstract

A method is described to quantify thermal conductance and temperature distributions with nanoscale resolution using scanning thermal microscopy. In the first step, the thermal resistance of the tip-surface contact is measured for each point of a surface. In the second step, the local temperature is determined from the difference between the measured heat flux for heat sources switched on and off. The method is demonstrated using self-heating of silicon nanowires. While a homogeneous nanowire shows a bell-shaped temperature profile, a nanowire diode exhibits a hot spot centered near the junction between two doped segments.

Electron transfer across a thermal gradient

“…More recently, noise (23)(24)(25)(26), nonlinear response (e.g., negative differential heat conductance), and control by external stimuli (27,28) have been examined. An important driving factor in this growing interest is the development of experimental capabilities that greatly improve on the ability to gauge temperatures (and "effective" temperatures in nonequilibrium systems) with high spatial and thermal resolutions (29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43) and to infer from such measurement the underlying heat transport processes. In particular, vibrational energy transport/ heat conduction in molecular layers and junctions has recently been characterized using different probes (6,19,(44)(45)(46)(47)(48)(49)(50)(51)(52).…”

Influence of anharmonic phonon decay on self-heating in Si nanowire transistors

“…[6][7][8][9] It is currently very challenging to experimentally determine the temperature profile or heat dissipation map of nanotransistors. 10 As an alternative numerical device simulations can be used to investigate the electro-thermal properties of not-yet-fabricated devices. To account for the strong quantum mechanical effects and the countable number of atoms that compose nanostructures a full-band and atomistic quantum transport simulator is needed where electron and phonon transport are self-consistently coupled through microscopic interactions.…”

Quantitative thermal microscopy using thermoelectric probe in passive mode

“…In spite of recent attempts to correct the effect of a probe contact 34,35 , quantitative measurements still remain generally inaccurate due to the dependence on the sample nature itself which is rarely considered. This is mainly due to the confusion between the actual surface temperature underneath the tip in contact and the actual temperature far beyond contact.…”