DEVELOPING Si DOPED GeTe AS A THERMOELECTRIC MATERIAL

The need of creating more efficient power in a highly technological era is taken on by thermoelectric materials. Their ability to transform thermal differences into electric potential and visa versa grants opportunities to improve old and new devices, from mechanical engines to mobile power banks. Utilization can be done by simple additions and modifications to working devices as well as new mechanism of operation, making thermoelectric materials vital for forthcoming technology and alternative energy.

The figure of merit ZT predicts a material’s ability to produce thermoelectric power efficiently, and is calculated using the Seebeck coefficient α, thermal conductivity k, electrical conductivity σ, and temperature T, as follows: ZT= α²σT/k. The attempt to increase ZT by optimizing one parameter often deters another, a motive to varying physical solutions such as phonon scattering. Another challenge is maintaining the figure ZT optimal over time.

This work focuses on developing GeSiTe as a thermoelectric material, with 1at% Si, by combining Ge_0.9Si_0.1 with GeTe. GeTe displays maximal thermoelectric properties within a lower temperature range compared to GeSi. The combination is done by arc furnace melting followed by a thermal treatment. The Seebeck coefficient, thermal conductivity and electrical conductivity are measured independently to calculate ZT. The combined material is expected to yield improved thermoelectric properties.