Thermoelectric materials allow conversions between heat and electricity. They can be used, e.g., for cooling applications or to make waste heat usable, which is important to preserve energy and reduce carbon emissions. Metal tellurides such as PbTe can be used for thermoelectric applications. However, a replacement for the toxic lead in PbTe would be useful. In addition, due to the low abundance of tellurium, thin-films are preferable to bulk materials for practical applications.
Gillian Reid, University of Southampton, UK, and colleagues have prepared [nBu3Sn(TenBu)] and used it as a single-source precursor for the deposition of continuous thin films of SnTe via low-pressure, low-temperature chemical vapor deposition (CVD). The team first ground tellurium into a powder, which was suspended in tetrahydrofuran (THF). Then they added an nBuLi solution, followed by as nBu3SnCl solution. The desired product was obtained in a yield of 86 %.
The synthesized [nBu3Sn(TenBu)] was then deposited onto fused silica substrates or TiN/SiO2 patterned substrates using low-pressure CVD. It allows film growth at significantly lower temperatures (355–434 °C) than are necessary when SnTe powder is used as the precursor. The thermoelectric properties of the SnTe thin films are comparable to other undoped SnTe materials. On TiN/SiO2 patterned substrates, the CVD results in selective growth on the TiN surfaces. This could allow for the controlled preparation of thin films, e.g., for microthermoelectric generators
- Low temperature CVD of thermoelectric SnTe thin films from the single source precursor, [nBu3Sn(TenBu)],
Fred Robinson, Daniel Newbrook, Peter Curran, Cornelis de Groot, Duncan Hardie, Andrew L. Hector, Ruomeng Huang, Gillian Reid,
Dalton Trans. 2020.