First-principles study on the electronic properties of BaCu sub(2)S sub(2)

• Published in: Physica. B, Condensed matter Vol. 405; no. 21; pp. 4582 - 4585
• Main Authors: Liu, G B, Wang, X Q, Kuang, X J, He, A L
• Format: Journal Article
• Language: English
• Published: 01.11.2010
• Subjects: Condensed matter; Conduction band; Density functional theory; Electronic properties; Mathematical analysis; Phases; Planes; Pseudopotentials
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2010.08.044

Using the pseudopotential plane-wave method under the density functional theory (DFT), the electronic properties of BaCu sub(2)S sub(2) in a and b phases are calculated. The result shows that the bottom conduction band is mainly made of Ba 5d state, while the upper valence band is formed by S 3p and Cu 4d states, but both of them for b-BaCu sub(2)S sub(2) are wider than those for a-BaCu sub(2)S sub(2). The electron and hole effective masses for BaCu sub(2)S sub(2) are also analyzed in detail. It is found that b-BaCu sub(2)S sub(2) has very small hole effective masses, which implies that b-BaCu sub(2)S sub(2) may possess a high hole mobility. Moreover, its hole effective masses are extremely anisotropic along ab plane and c axis. These properties are helpful to enhance its Seebeck coefficient, and means that b-BaCu sub(2)S sub(2) could be a good candidate of thermoelectric materials.