Improved thermoelectric performance of Bi₂Se₃ alloyed Bi₂Te₃ thin films via low pressure chemical vapour deposition

Abstract

Thermoelectric generators are attractive for autonomous sensor systems where regular battery replacement would not only cause an increase in the maintenance costs and discontinuity in the operation, but also destroy the concept of a truly autonomous system. Micro-thermoelectric generators utilise thin films of material for energy harvesting which can greatly reduce the amount of material used, which is especially important for rare elements such as tellurium. Thin films of Bi₂Te₃ were successfully prepared via a single source precursor CVD method. The thermoelectric performance of these films is improved by alloying a Bi₂Se₃ precursor to deposit ternary Bi₂Te_3-xSe_x. The composition of the ternary system is tuned to optimise the combination of carrier concentration and mobility to give a three-fold enhancement of the thermoelectric power factor at 300 K, and six-fold enhancement at 500 K, with respect to Bi₂Te₃. This improvement from the substitution of Te with Se is believed to be due to donor effects, as well as point defects caused by this substitution.

More information

Identifiers

ORCID for Daniel W Newbrook: orcid.org/0000-0002-5047-6168

ORCID for Victoria Greenacre: orcid.org/0000-0002-3381-9616

ORCID for Andrew L. Hector: orcid.org/0000-0002-9964-2163

ORCID for William Levason: orcid.org/0000-0003-3540-0971

ORCID for Gillian Reid: orcid.org/0000-0001-5349-3468

ORCID for C.H. De Groot: orcid.org/0000-0002-3850-7101

ORCID for Ruomeng Huang: orcid.org/0000-0003-1185-635X

Catalogue record

Export record

Altmetrics