Defect-Engineering for Si Thermoelectrics

PhD Student: Mr Neil Wight
Supervisor: Dr Nick Bennett
Funder: EPSRC (Doctoral Training Award)

Si is a remarkably useful element. Its abundance, low cost and low toxicity, combined with vast practical know-how means it is a leading material on which to base technologies. However for good reason, certain applications have under-utilised it, with thermoelectrics being one example.

Thermoelectric performance is governed by a materials’ thermoelectric power factor and thermal conductivity. Compared to other materials, highly-doped Si has desirably large power factor, but this is negated by high thermal conductivity, meaning that thermoelectric performance is relatively poor for bulk Si, about 100-fold worse than for popular materials such as bismuth telluride.

This study is investigating the introduction of defects in Si as a means to reduce the thermal conductivity in Si nano-films.