First-Principles Prediction of Structural, Elastic, Mechanical, and Electronic Properties of Cu2ZnSnS4 under Pressure

Abstract

Quaternary compounds are high desirable for realizing advanced optoelectronic and spintronic devices. In this paper, we have systematic studied the effects of pressure on the structural, elastic, mechanical, and electronic properties of Cu2ZnSnS4 by means of first-principles calculations. The results indicated that both the lattice constant and cell volume decrease with the increase of pressure, which are matched well with available previous values. The pressure has a more significant influence on the c direction than the a and b direction. The obtained elastic constants reveal the Cu2ZnSnS4 is mechanically stable between 0 GPa and 15 GPa. The bulk modulus, shear modulus, and Young’s modulus are evaluated by Voigt-Reuss-Hill approximation. All these elastic moduli exhibit a monotonic feature as a function of pressure. The Poisson’s ratio, Pugh’s criterion, and Cauchy pressure indicate that the quaternary compound Cu2ZnSnS4 is ductile against pressure. Meanwhile, the analysis of the electronic structures reveals that the states near the valence band top are derived from Cu 3d and S 3p orbitals, and the lowest conduction band is composed of Sn 5s and S 3p orbitals. We expect that the findings predicted the physical properties of this compound will promote future experimental studies on Cu2ZnSnS4.