Growth and characterization of QDSL (Quantum Dots Superlattices) of metal silicides in an n-doped SiGe matrix for thermoelectric applications

We studied the growth of QDSLs (Quantum Dots Superlattices) made of Ti₅Si₃ quantum dots inside an “n” doped SiGe thin film matrix using a commercial Chemical Vapor Deposition (CVD) apparatus. To our knowledge, it is the first time these kinds of materials are produced. XRD, SEM and TEM images were employed to characterize the obtained materials. As predicted by the theory, the inclusion of these particles resulted on a reduction of the material´s thermal conductivity for monocrystalline samples. Moreover, a significant increase on the Seebeck coefficient was observed without increasing the electrical resistivity. By using these materials for thin film thermoelectric devices, an increase of the efficiency is expected when compared to SiGe thin films.