ANR NanoBiPelt : Nanometric Bismuth wire / nanoporous silica composites for Peltier cooling

_{ANR NACRI (ANR project : 2020-2024)}

Project coordinator :

Claire Levelut, L2C, Montpellier

Partners :

L2C, Université de Montpellier
ICGM Université de Montpellier
Institut Neel Grenoble

ANR Collaborative Research Program (PRC) :

Contrat ANR- 19-CE09-0019-01
CE19 : Functional nano-objects and nanomaterials, interfaces

Project goal :

To develop new nanocomposites for Peltier cooling devices with performance surpassing current technologies.

*EDX map showing the presence of bismuth in the pores of mesoporous alumina*

Nanostructuring offers a promising route to significantly enhance the efficiency of the best thermoelectric materials, particularly in Peltier devices. Theoretical predictions made about twenty years ago suggested that ultra-thin Bi-Sb nanowires could exhibit exceptional thermoelectric properties.

In this project, Bi-Sb nanowires with diameters of 0.5–5 nm are incorporated into the pores of mesoporous matrices (zeolites, silica, or alumina) to enhance the electronic properties of bismuth while strongly reducing its thermal conductivity. This strategy enables a substantial increase in the figure of merit ZT of Bi-Sb alloys, already among the best thermoelectric materials in the 100–300 K temperature range in bulk form.

An innovative high-pressure, high-temperature fabrication method is employed to produce homogeneous crystalline nanowires with small diameters. Their structure and physical properties, particularly thermoelectric performance, are studied as a function of nanowire diameter. The confinement of the nanowires is analyzed using vibrational microspectroscopies such as IR and Raman.

The thermoelectric performance of these nanocomposites is then quantified to design efficient cooling devices without the need for cryogenic fluids.