Nanostructured Thermoelectric Films Synthesised by Spark Ablation and Their Oxidation Behaviour

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 Bi(2)Te(3). The lowest achieved thermal conductivity was <0.1 W m [Formula: see text] K [Formula: see text] at room temperature with a mean nanoparticle size of [Formula: see text] nm and a porosity of 44%. This is comparable to the best published nanostructured Bi(2)Te(3) 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.