Studies on the thermal stability of BiCuSeO

•Decomposition and oxidation mechanisms of BiCuSeO were studied.•BiCuSeO does not volatilize in inert atmosphere up to 650 °C.•BiCuSeO starts oxidizing for temperatures as low as 200 °C.

BiCuSeO based materials have been reported as very promising thermoelectric materials, with thermoelectric figure of merit values that make them among the best p-type Pb-free polycrystalline thermoelectric materials, and they could be suitable for applications in thermal to electrical power conversion modules in a 300–650 °C temperature range. In this paper, we report on the phase stability and thermal stability of these materials under inert and oxidizing atmosphere and we discuss their actual potential for wide scale applications. We show that although they are stable in inert atmosphere up to 650 °C, with very slow volatilization rate, it is not the case under oxidizing atmosphere, with a quick oxidation starting at a moderate temperature.

Graphical abstractBiCuSeO oxidation under air, starting below 300 °C Figure optionsDownload full-size imageDownload as PowerPoint slide