Born effective charges of Cu2ZnSnS4 quaternary compound: First principles calculations

T. A. Oliveira, J. Coutinho and V. J. B. Torres; Thin Solid Films 535 311 (2013)


Toxicity and scarceness stand as major handicaps for CuInGaSe2 and CuInGaS2 based compounds when applied as photoactive layers in solar cells. As a result, quaternary semiconductors Cu2ZnSnS4 and Cu2ZnSnSe4 are emerging as serious contenders to take their place. We report on the structural and dynamical properties of Cu2ZnSnS4 by using first principles plane-wave pseudopotential calculations. The most stable kesterite and stannite structures were considered and the Born effective charge (transverse charge) tensors were obtained by using self-consistent finite-electric field calculations within the Berry phase approach. These quantities may allow us to understand longitudinal and transverse optical splittings from vibrational spectra of this class of materials and related alloys.