Theoretical Search for p-Type Dopants in Mg2X (X= Si, Ge) Semiconductors for Thermoelectricity
Electronic structure calculations of doped Mg2(Si-Ge) semiconductors were performed by the charge self-consistent Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA) in order to search for p-type impurities. It was predicted that Li and Na (located on Mg site) as well as B, Ru, Mo and W (located on Si site) are expected to behave as hole donors in Mg2(Si-Ge). Using the calculated density of states in doped Mg2Si in the vicinity of the Fermi level, the linear term of thermopower was also estimated from the simplified Mott's formula. The RT Seebeck coefficient may range from 120μV/K (Li) to almost 300μV/K (Ru) at the 1% content of doped impurities.
Yuriy Verbovytskyy and António Pereira Gonçalves
J. Toboła et al., "Theoretical Search for p-Type Dopants in Mg2X (X= Si, Ge) Semiconductors for Thermoelectricity", Solid State Phenomena, Vol. 194, pp. 266-271, 2013