skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Functional Domain Walls as Active Elements for Energy Technology

Abstract

In the past five years in the duration of this project (July 2011-July 2016), we have made a wide range of achievements in both basic research and energy applications along the direction planned in the original proposal. These achievements were reflected by 13 articles published in peer-reviewed journals including Nature Communications, Nano Letters, etc., and one currently in revision at Science. These papers have been accumulatively cited for more than 660 times as of October 2016, according to Web of Science statistics. Specifically, we have made impactful discoveries in the following fields. Basic Research. We have investigated in depth the materials physics of the representative quantum material, VO2, on which most of our project is anchored. We have discovered that independent diffusion of heat and charge in the absence of quasiparticles in metallic VO2 leads to an anomalously low electronic thermal conductivity, dramatically violating the Wiedemann-Franz law, which is a robust law governing behavior of normal conductors stating that free electrons transport heat proportionally to the charge they transport. In addition, we have discovered a peculiar thermal rectification effect based on its phase transition, as well as a gating response of the phase transition. In parallel to the work onmore » VO2, we have also made breakthroughs in investigation of transition metal dichalcogenides (TMDs): we have experimentally demonstrate a strong anisotropy in in-plane thermal conductivity of black phosphorous, discovered a new, unusual member of the TMDs family, ReS2, where the bulk behaves as monolayers due to electronic and vibrational decoupling, unusual interaction between physi-sorbed molecules and 2D semiconductors, and thermally driven crossover from indirect toward direct bandgap in some 2D TMDs. Applications. Based on the understanding and knowledge gained from the basic investigation, we have developed novel tools and devices for energy applications. These include a nanowire based microthermometer for quantitative evaluation of electron beam heating in electron microscopy, giant-amplitude, high-work density microactuators and torsional micromuscles, as well as nanoscale thermometers and powermeters, all based on the VO2 phase transition.« less

Authors:
ORCiD logo [1]
  1. Univ. of California, Berkeley, CA (United States)
Publication Date:
Research Org.:
Univ. of California, Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1328709
Report Number(s):
DOE-Berkeley-0006397
DOE Contract Number:  
SC0006397
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; phase transition; 2D materials

Citation Formats

Wu, Junqiao. Functional Domain Walls as Active Elements for Energy Technology. United States: N. p., 2016. Web. doi:10.2172/1328709.
Wu, Junqiao. Functional Domain Walls as Active Elements for Energy Technology. United States. https://doi.org/10.2172/1328709
Wu, Junqiao. 2016. "Functional Domain Walls as Active Elements for Energy Technology". United States. https://doi.org/10.2172/1328709. https://www.osti.gov/servlets/purl/1328709.
@article{osti_1328709,
title = {Functional Domain Walls as Active Elements for Energy Technology},
author = {Wu, Junqiao},
abstractNote = {In the past five years in the duration of this project (July 2011-July 2016), we have made a wide range of achievements in both basic research and energy applications along the direction planned in the original proposal. These achievements were reflected by 13 articles published in peer-reviewed journals including Nature Communications, Nano Letters, etc., and one currently in revision at Science. These papers have been accumulatively cited for more than 660 times as of October 2016, according to Web of Science statistics. Specifically, we have made impactful discoveries in the following fields. Basic Research. We have investigated in depth the materials physics of the representative quantum material, VO2, on which most of our project is anchored. We have discovered that independent diffusion of heat and charge in the absence of quasiparticles in metallic VO2 leads to an anomalously low electronic thermal conductivity, dramatically violating the Wiedemann-Franz law, which is a robust law governing behavior of normal conductors stating that free electrons transport heat proportionally to the charge they transport. In addition, we have discovered a peculiar thermal rectification effect based on its phase transition, as well as a gating response of the phase transition. In parallel to the work on VO2, we have also made breakthroughs in investigation of transition metal dichalcogenides (TMDs): we have experimentally demonstrate a strong anisotropy in in-plane thermal conductivity of black phosphorous, discovered a new, unusual member of the TMDs family, ReS2, where the bulk behaves as monolayers due to electronic and vibrational decoupling, unusual interaction between physi-sorbed molecules and 2D semiconductors, and thermally driven crossover from indirect toward direct bandgap in some 2D TMDs. Applications. Based on the understanding and knowledge gained from the basic investigation, we have developed novel tools and devices for energy applications. These include a nanowire based microthermometer for quantitative evaluation of electron beam heating in electron microscopy, giant-amplitude, high-work density microactuators and torsional micromuscles, as well as nanoscale thermometers and powermeters, all based on the VO2 phase transition.},
doi = {10.2172/1328709},
url = {https://www.osti.gov/biblio/1328709}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Oct 12 00:00:00 EDT 2016},
month = {Wed Oct 12 00:00:00 EDT 2016}
}