title: Polytypism and Unique Site Preference in LiZnSb: A Superior Thermoelectric Reveals Its True Colors.
abstract: The first example of polytypism in the I-II-V semiconductors has been demonstrated with the synthesis of cubic LiZnSb by a low-temperature solution-phase method. This phase exhibits a unique coloring pattern that is novel for this class of compounds. The choice of site configuration has a considerable impact on the band structure of these materials, which in turn affects the transport properties. While the hexagonal polytype has been suggested as a promising n-type and extremely poor p-type thermoelectric material, the cubic analogue is calculated to have high efficiencies for both the n- and p-type derivatives (1.64 and 1.43, respectively, at 600 K). Furthermore, the cubic phase is found to be the energetically favored polytype. This surprising result provides a rationale for the lack of success in synthesizing the hexagonal polytype in either stoichiometric or n-type compositions.
authors.affiliation: Department of Chemistry, Iowa State University , Ames, Iowa 50011, United States.
authors.forename: Miles A
authors.initials: MA
authors.lastname: White
authors.affiliation: Department of Chemistry, Iowa State University , Ames, Iowa 50011, United States.|U.S. DOE Ames Laboratory , Ames, Iowa 50011, United States.
authors.forename: Gordon J
authors.initials: GJ
authors.lastname: Miller
authors.affiliation: Department of Chemistry, Iowa State University , Ames, Iowa 50011, United States.|U.S. DOE Ames Laboratory , Ames, Iowa 50011, United States.
authors.forename: Javier
authors.initials: J
authors.lastname: Vela