Increasing Seebeck Coefficients and Thermoelectric Performance of Sn/Sb/Te and Ge/Sb/Te Materials by Cd Doping

Ge and Sn in (GeTe) n Sb 2 Te 3 (GST) and (SnTe) n Sb 2 Te 3 compounds, respectively, are partially substituted by Cd. These layered compounds ( n = 1) consist of NaCl‐type slabs that are separated by van der Waals gaps. Resonant X‐ray diffraction yields different Cd‐atom distributions in Cd 0.2 Ge 0.8 Sb 2 Te 4 and Cd 0.2 Sn 0.8 Sb 2 Te 4 , which indicate how van der Waals gaps in metastable cubic GeTe‐rich or SnTe‐rich compounds ( n ≥ 7) are...