Nanostructured Thermoelectric Films Synthesised by Spark Ablation and Their Oxidation Behaviour
Hendrik Joost van Ginkel,
Lisa Mitterhuber,
Marijn Willem van de Putte,
Mark Huijben,
Sten Vollebregt,
Guoqi Zhang
Affiliations
Hendrik Joost van Ginkel
Department of Microelectronics, Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, 2628 CD Delft, The Netherlands
Lisa Mitterhuber
Materials Center Leoben Forschung GmbH, A-8700 Leoben, Austria
Marijn Willem van de Putte
MESA+ Institute for Nanotechnology, University of Twente, 7522 NH Enschede, The Netherlands
Mark Huijben
MESA+ Institute for Nanotechnology, University of Twente, 7522 NH Enschede, The Netherlands
Sten Vollebregt
Department of Microelectronics, Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, 2628 CD Delft, The Netherlands
Guoqi Zhang
Department of Microelectronics, Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, 2628 CD Delft, The Netherlands
Reducing the thermal conductivity of thermoelectric materials has been a field of intense research to improve the efficiency of thermoelectric devices. One approach is to create a nanostructured thermoelectric material that has a low thermal conductivity due to its high number of grain boundaries or voids, which scatter phonons. Here, we present a new method based on spark ablation nanoparticle generation to create nanostructured thermoelectric materials, demonstrated using Bi2Te3. The lowest achieved thermal conductivity was −1 K−1 at room temperature with a mean nanoparticle size of 8±2 nm and a porosity of 44%. This is comparable to the best published nanostructured Bi2Te3 films. Oxidation is also shown to be a major issue for nanoporous materials such as the one here, illustrating the importance of immediate, air-tight packaging of such materials after synthesis and deposition.
