cfaed Seminar Series

cfaed Seminar Series

Dr. Jose Ordonez-Miranda , Centre National de la Recherche Scientifique Institute Pprime, France

Thermal Transistor Based on the Hysteresis of VO2

10.11.2016 (Thursday) , 13:00 - 14:00
Seminar Room 115 (HAL) , Hallwachsstr. 3 , 01187 Dresden

Guiding, amplification, and control of electrical and thermal currents are of critical importance
to efficiently manage the energy resources present in nature. In electricity, this has been done
with diodes and transistors, which have allowed the development of almost all modern
electronics, while the conception of the thermal diode/transistor has recently emerged. These
fundamental thermal devices are based on the dielectric-metal transition of phase change
materials (PCMs) and were reported to provide fine control on heat currents, however up to
date, not so much attention has been put neither on the intrinsic thermal hysteresis of PCMs
nor on temperature control, which are considered in the present work.
The objective of this talk is to theoretically demonstrate that a thermal transistor with a PCM
base can be used as a thermal device for heating and cooling. This is done by exploiting the
effect of the PCM thermal hysteresis on the heat fluxes that the base exchanges with the
collector and emitter of the transistor. Based on the principle of energy conservation, we show
that these heat fluxes and the base temperature undergo significant jumps under a small
modification of the heat flux applied to the base. When the collector and emitter of the
transistor operate at 350 K and 300 K, respectively, a temperature jump of +18 K (-5 K) and a
coefficient of performance of 58% (32%) are obtained during the heating (cooling) of a VO2
base excited with 208 Wm-2 (63 Wm-2). This sizeable thermal effect is dominated by the photon
heat current and could provide an alternative and/or complement to the present refrigeration
and heating technologies involved in freezers, microwave ovens, and radiators used at home.

research area is the transport of heat by phonons, photons, electrons, and polaritons
propagating in nanomaterials with applications in thermotronics. The Boltzmann transport
equation and Maxwell's equations of electromagnetism are his main tools of theoretical
He obtained his bachelor degree in applied physics at the National University Jorge
Basadre Grohmann in Tacna, Peru and received his Master in Physics from CINVESTAV
in Merida, Mexico. Jose holds a Ph.D. degree in physics granted by CINVESTAV and the
University of Boulder in Colorado, USA. He performed a postdoc in the laboratory EM2C
at the Ecole Centrale Paris, and was recruited by the CNRS in October 2015, for which
he currently works as a full researcher.
As a result of his research activities, since he began his Ph.D. studies in 2008, Jose has
published 46 scientific papers and one book chapter. His Ph.D. thesis has been
recognized by CINVESTAV and UNAM as the best doctoral thesis in sciences and
materials sciences of Mexico in 2011, respectively. In addition, he was awarded the prize
of outstanding young researcher granted by the International Society of photothermal
phenomena, in 2014, in Shanghai, China.

Go back