E-viri
PDF
Recenzirano
Odprti dostop
-
Zólyomi, V.; Drummond, N. D.; Fal'ko, V. I.
Physical review. B, Condensed matter and materials physics, 05/2013, Letnik: 87, Številka: 19Journal Article
We report density-functional-theory calculations of the electronic band structures and optical absorption spectra of two-dimensional crystals of Ga sub(2)X sub(2) (X = S, Se, and Te). Our calculations show that all three two-dimensional materials are dynamically stable indirect-band-gap semiconductors with a sombrero dispersion of holes near the top of the valence band. We predict the existence of Lifshitz transitions-changes in the Fermi-surface topology of hole-doped Ga sub(2)X sub(2)- at hole concentrations n sub(s) = 7.96 x 10 super(13) cm super(-2), n sub(Se) = 6.13 x 10 super(13) cm super(-2), and n sub(Te) = 3.54 x 10 super(13) cm super(-2).
