Abstract
Thermal energy transfer and dissipation processes can influence the physical properties of matter, control the kinetics of chemical reactions, and trigger bio-molecular mechanisms in living organism. Understanding how thermal phenomena arise and change as the characteristic length scale of structures becomes comparable to or even shorter than the mean free path of energy carriers such as electrons and phonons is therefore on of the key challenges in the physical sciences.
In this seminar, I will present experimental routs to characterize local energy dissipation in nanoscale electronic devices [1,2] and thermal transport in molecular structures [3,4] based on scanning probe microscopy and micro-electromechanical systems (MEMS) with integrated temperature sensors [5]. Based on numerous examples, I will illustrate how scanning probe thermometry enables the real-space imaging of local Joule and Peltier effects in semiconductor devices down to 10 nm spatial and tens of pico-Watt heat flux resolution [1]. In addition, I will discuss the study of thermal transport across scaled contacts [6], ultimately demonstrating the validity of fundamental charge and heat transfer relations down to the atomic scale [5].
Finally, I will provide an outlook on our developments of energy and time-resolved photo-thermal scanning probe techniques [4], and their unique potential to unravel local thermo-physical processes in quantum materials and molecular systems.
References:
[1] F. Menges et al., Temperature mapping of operating nanoscale devices by scanning probe thermometry, Nature Com. 7, 10874, 2016.
[2] F. Menges et al., Nanoscale thermometry by scanning thermal microscopy, Review of Scientific Instruments (87) 7, 074902, 2016.
[3] T. Meier et al., Length-dependent thermal transport along molecular chains, Physical review letters 113 (6), 060801, 2014.
[4] BT. O’Callahan et al, Photo-induced tip-sample forces for chemical nanoimaging and spectroscopy,Nano-letters 18(9), 5499-5505, 2018.
[5] N. Mosso et al., Heat transport through atomic contacts, Nature Nanotechnology 12, 430-433, 2017.
[6] F. Menges et al., Thermal transport into graphene through nanoscopic contacts, Physical review letters 111 (20), 205901, 2013.
