Mg₂Si film on Si(111) prepared by Ultra-Fast Mg reactive deposition: crystal structure and thermoelectric properties

The Mg2Si film (similar to 800 nm thick) was grown by pulsed reactive deposition of Mg on Si(111) at 340 degrees C in UHV. Structural investigations by XRD, SEM and cross-sectional x-HR-TEM demonstrate high crystal quality and 100% texture of the film. Thermoelectric properties of the Mg2Si film are characterized within 290-470 K. The film conductivity changes from p-type below 309 K to n-type at higher temperatures. The power factor is 0.27 mW/mxK(2) at 470 K. The p-type conductivity can be associated with presence of oxygen or/ and vacancies (V-Mg, V-Mg2Si).