Developments on Thermometric Techniques in Probing Micro- and Nano-heat

Abstract

Temperature is always of fundamental importance in various microscopic systems ranging from solid state nano-devices physics, chemical micro-reactions and biological cells. As traditional thermometers for macroscopic systems are not applicable in microscopic systems, alternative tools have to be developed to measure temperature at micro-and nano-scale. We provide here are view of the main currently available micro-and nano-thermometry tools including microscopic infrared thermometer, thermoreflectance, micro-Raman, plasmon energy expansion thermometry (PEET), Diamond thermometers, nanomaterial-based nanothermometers and two thermometric techniques based on scanning probe microscope (SPM), namely, scanning thermal microscope (SThM) and our recently-developed scanning noise microscope at terahertz (SNoiM).

Enhanced Peltier Effect in Wrinkled Graphene Constriction by Nano‐Bubble Engineering

“…SThM is conducted in conjunction with non‐equilibrium scanning thermometry to map the temperature difference in the graphene devices (see the Experimental Section). [ 21,22 ] As shown in Figure a, during the SThM measurements, an AC voltage V bias at f exc = 313 Hz is applied to the device metal contacts and as the AC current passes through the graphene channel, the thermoelectric phenomenon including Peltier heating/cooling occurs in addition to Joule heating. The temperature difference is monitored by a SThM tip integrated with a thermocouple at the tip apex as the graphene channel is scanned.…”

Anisotropic Hot-Electron Kinetics Revealed by Terahertz Fluctuation

“…For instance, Raman scattering spectroscopy − is sensitive to the lattice (phonon modes) but insensitive to conduction electrons. As a consequence, despite recent extensive interests in nanothermometry studies, experimental evidence for clarifying nanoscopic hot-electron effects − , remains to be mostly indirect so far. In fact, only lattice temperature ( T L ), rather than the effective electron temperature ( T e ), is probed in most of the previous works, making the thermal properties and microscopic kinetic behaviors of hot electrons largely unexplored up to now.…”