Session: 08-01: Micro/Nanoscale Heat Conduction

Paper Number: 140762

140762 - Thermal Transport Study in Telescopic Nanowires Through Raman Thermometry 

Abstract: 

Heat dissipation has become a critical problem in the performance of electronic devices, thus reducing their lifespans. To cope with this, researchers are using several approaches like thermoelectric generators, coolers, thermal diodes, heat guides and more [2]. In our current research, we have studied telescopic nanowires for their thermal transport capabilities as a medium for manipulating heat flow.

A telescopic nanowire is a quasi-one-dimensional structure with a thick and a thin part having diameters of 300 and 90 nm, respectively, with a transition region in between. The GaAs telescopic nanowires are grown by MBE technique using the VLS mechanism and the transition from the thick to the thin part is done by modulating the flow of precursors.

The thermal transport measurement in telescopic nanowires was done by bridging the nanowire between the suspended platforms of the thermal bridge devices. Thermal bias was applied by Joule heating the platforms and measuring the temperature rise due to the thermal transport through the nanowire on the sensor side. Using the slopes of temperature rise of the heating and sensing platforms with power dissipated, the thermal conductance was calculated in forward and reverse bias conditions. The values of thermal conductances lie between 1E−9 W/K and 20E−9 W/K between different measured GaAs telescopic nanowires.

An equivalent model of the thermal circuit for the experimental system of telescopic nanowires was developed. Further, the temperature jump at the contacts is extracted using Raman thermometry [6] while applying different temperature biases. In our case, a thermal contact resistance of (2.71 ± 8.43) × 10^8 K/W was estimated and compared to reference homogeneous nanowires. The underestimation of the thermal conductance of the telescopic nanowire measured approximately 2E−9 W/K from the standard thermal bridge method was corrected to around 6E−9 W/K via Raman thermometry. The thermal mapping using a laser as a local temperature probe along the nanowire axis was used to extract the thermal conductivity of the corresponding thick and thin parts. Further, the total thermal conductance obtained from the sum of the series conductances of contacts and nanowires from the thermal circuit was estimated and found in agreement with the thermal conductance measured through the standard thermal bridge method.

These results underscore the significance of accounting for thermal contact resistance in accurately characterizing the thermal properties of nanowire-based systems. The electro-opto thermal thermal measurements proved very powerful for studying the nanowire system in depth. Moreover, this is the first comprehensive thermal transport study on telescopic nanowires performed experimentally. 

Presenting Author: Yashpreet Kaur Univeristy of Basel

Presenting Author Biography: Yashpreet Kaur
Birth date: 04/04/1993
Nationality: Indian
email: yashpreet.kaur@unibas.ch

Ph.D, Physics, University of Basel Basel, Switzerland, May 2019 - November 2023
• Thesis title: Thermal Rectification in designed nanowires

MSc. Nanosciences, Universit´e Grenoble Alpes Grenoble, France 2017 – 2018
• Thesis topic: Development and optimization of a process for producing photonic structures
by sawing planar guides.

Masters in Applied Physics 2014 – 2016, Amity University Noida, Delhi NCR, India
• Thesis topic: Modeling and Simulations of Piezoelectric Cantilevers for Energy Harvesting
Applications. Simulation Tools: Intellisuite and COMSOL Softwares

M.D. University Rohtak, India
Bachelor of Education 2012 – 2013

Miranda House, University of Delhi Delhi, India
Bachelor of Physics 2009 – 2012

Authors:

Yashpreet Kaur Univeristy of Basel
Saeko Tachikawa University of Basel
Jose Manuel Sojo Gordillo University of Basel
Milo Yaro Swinkels University of Basel
Matteo Camponovo Univeristy of Basel
Miquel Lopez-Suarez Institut de Ciencia de Materials de Barcelona (ICMAB-CSIC)
Wonjong Kim ́Ecole Polytechnique F ́ederale de Lausanne
Anna Fontcuberta I Morral Ecole Polytechnique F ́ederale de Lausanne
Riccardo Rurali nstitut de Ciencia de Materials de Barcelona (ICMABCSIC)
Ilaria Zardo Univeristy of Basel