MRS Meetings and Events


EL06.08.02 2024 MRS Spring Meeting

Solid-State Electrochemical Thermal Transistor based on Oxygen Sponge SrCoOx (2 ≦ x ≦ 3)

When and Where

Apr 25, 2024
2:00pm - 2:30pm

Room 343, Level 3, Summit



Hiromichi Ohta1

Hokkaido University1


Hiromichi Ohta1

Hokkaido University1
Thermal transistors are devices that can electrically switch “heat flow” on and off, like a semiconductor transistor that switches “electric current” on and off. We can reuse waste heat exhausted to the environment using devices composed of thermal transistors such as thermal shutters and thermal displays<sup> [1]</sup>. Although several thermal transistors have been demonstrated thus far, the use of liquid electrolytes (or ionic liquids or ion gels) may limit the application from the viewpoint of reliability or liquid leakage<sup> [2−4]</sup>. Very recently, we demonstrated a solid-state thermal transistor that can electrochemically control the heat flow with an on-to-off ratio of the thermal conductivity (<i>κ</i>) of ~4 without using any liquid<sup> [5]</sup>. The thermal transistor is composed of a multilayer film composed of an upper electrode (Pt), strontium cobaltite (SrCoO<i><sub>x</sub></i>), solid electrolyte (YSZ), and bottom electrode (Pt). An electrochemical redox treatment at 280 °C in air repeatedly modulates the crystal structure and <i>κ</i> of the SrCoO<sub><i>x</i></sub> layer. The fully oxidized perovskite-structured SrCoO<sub>3</sub> layer shows a high <i>κ</i> ~3.8 W m<sup>−1</sup> K<sup>−1</sup>, whereas the fully reduced defect perovskite-structured SrCoO<sub>2</sub> layer shows a low <i>κ</i> ~0.95 W m<sup>−1</sup> K<sup>−1</sup>. We believe that all-solid-state electrochemical thermal transistors have the potential to become next-generation devices for future thermal management technology, and we are currently working on improving their characteristics<sup> [6, 7]</sup>.<br/><br/><b>References</b><br/>[1] T. Swoboda <i>et al.</i>, <i>Adv. Electron. Mater.</i> <b>7</b>, 2000625 (2021).<br/>[2] J. Cho <i>et al</i>., <i>Nat. Commun.</i> <b>5</b>, 4035 (2014).<br/>[3] A. Sood <i>et al</i>., <i>Nat. Commun.</i> <b>9</b>, 4510 (2018).<br/>[4] Q. Y. Lu <i>et al</i>., <i>Nat. Mater.</i> <b>19</b>, 655 (2020).<br/>[5] Q. Yang, <u>H. Ohta</u> <i>et al</i>., <i>Adv. Funct. Mater.</i> <b>33</b>, 2214939 (2023).<br/>[6] Z. Bian, <u>H. Ohta</u> <i>et al</i>., <i>ACS Appl. Mater. Interfaces</i> <b>15</b>, 23512 (2023).<br/>[7] M. Yoshimura, <u>H. Ohta</u> <i>et al</i>., <i>ACS Appl. Electron. Mater.</i> <b>5</b>, 4233 (2023).


electrical properties | thermal conductivity

Symposium Organizers

Aiping Chen, Los Alamos National Laboratory
Woo Seok Choi, Sungkyunkwan University
Marta Gibert, Technische Universität Wien
Megan Holtz, Colorado School of Mines

Symposium Support

Korea Vacuum Tech, Ltd.

Center for Integrated Nanotechnologies, Los Alamos National Laboratory
Radiant Technologies, Inc.

Publishing Alliance

MRS publishes with Springer Nature