Enhanced Thermoelectric Properties of SrSi₂ Composite Films with Cubic and Layered Polymorphs

High Resolution Image Download MS PowerPoint Slide SrSi 2 composite films exhibit a significant improvement in thermoelectric performance through the mixture of the stable cubic phase with a metastable layered phase. The phase fraction of the cubic and layered phases in SrSi 2 films is controlled by changing the deposition temperature. The film deposited at 700 °C, which is composed of a semimetallic cubic phase and a small portion of a metallic layered phase, shows a high figure of merit, ZT, beyond 0.4 at around room temperature. This value is eight times larger than the previously reported one for cubic SrSi 2 bulk polycrystals. These large values originate from the microstructures of the films, which reduce thermal conductivity without deterioration of the power factor.