First-principles investigation on electronic structure, magnetic states and optical properties of Mn-doped SnS2 monolayer via strain engineering.

Two-dimensional magnetic materials are high desirable for realizing advanced optoelectronic and spintronic devices. In this paper, we report systematic studies the effects of strain on the electronic structure, magnetic states and optical properties of Mn-doped SnS 2 monolayer (ML) by means of first-principles calculations. Ab-initio molecular dynamics simulations and formation energy reveal that the Mn-doped SnS 2 ML is stable at 500 K and can be fabricated under the S-rich condition. The substitution of a Mn for a Sn atom induces 3 μ B magnetic moment in nonmagnetic SnS 2 ML, which is consistent with the Hund's rule and Aufbau principle. Based on classical Heisenberg model and mean-field approximation the Curie temperature is calculated to be 476.13 K. Due to symmetry reserved crystal structure, the net magnetic moment of Mn-doped SnS 2 ML is robust even if considerable strains (−10 to 10%) are applied. The blue-shift and red-shift of the absorption peaks are observed in the optical spectrum by biaxial compressive and tensile strains. The biaxial strain effectively improves the optical properties of Mn-doped SnS 2 ML, particularly in the visible light region. This study provide useful guidance for practical application in magnetic and optoelectronic devices. The VBM and CBM shifts of the Mn-doped SnS 2 ML under biaxial strain. [Display omitted] • The electronic, magnetic and optical properties of Mn-doped SnS 2 monolayer are studied. • Mn-doped SnS 2 monolayer is stable at 500 K and can be fabricated under S-rich condition. • Under biaxial strain the Mn-doped SnS 2 monolayer is always a magnetic semiconductor with 3 μ B moment. • The optical properties of Mn-doped SnS 2 monolayer can be tuned by biaxial strain. • Mn-doped SnS 2 monolayer is a vigorous nominee for optoelectronic applications. [ABSTRACT FROM AUTHOR]