Modulating the electronic, magnetic and optical properties of 1T-SnSe2 monolayer by defects: An ab initio study. (September 2020)

• Record Type: Journal Article
• Authors: Ali, Anwar; Zhang, Jian-Min; Muhammad, Iltaf; Shahid, Ismail; Ahmad, Iqtidar
• Is Part Of: Superlattices and microstructures. Volume 145(2020)
• Publication Date: 2020-09
• Subjects: 1T-SnSe2 monolayer -- Defects -- Electronic properties -- Magnetic properties -- Optical properties -- GGA+U; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2020.106621
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: We investigate the effect of vacancies and doping on the electronic, magnetic and optical properties of 1T-SnSe2 monolayer by using density functional theory calculations. The results reveal that the semiconducting 1T-SnSe2 monolayer becomes a half-metal on creating one tin vacancy (V1Sn ), while it is still a semiconducting on creating one selenium vacancy (V1Se ), two selenium vacancy (V2Se ), as well as one tin and one selenium vacancy (V1Sn+1Se ). The V1Sn and V1Sn+1Se vacancies induce magnetic ground states with net magnetic moments of 4 and 2 μB respectively, while the V1Se and V2Se vacancies induce nonmagnetic ground states. In Mo-doped 1T-SnSe2 monolayer, crystal-field splitting of Mo-4d orbital in the octahedral environment induces net magnetic moment of 2 μB . The band structure and density of states also show that the Mo-doped system is a magnetic semiconductor. In addition, the defective 1T-SnSe2 mononlayer can also enhanced the absorption efficiency of the solar energy, particularly in the infrared region. An interesting red-shift phenomenon has been observed in the curves of imaginary part of the dielectric function and absorption spectra for the defect systems, suggesting their quite promising applications in optoelectronic devices. Graphical abstract: The top view atomic models of 1T-SnSe2 monolayer with (a) V1Sn vacancy, (b) V1Se vacancy, (c) V1Sn+1Se vacancy, (d) V2Se vacancy and (e) Mo-doped. Image 1 Highlights: 1T-SnSe2 monolayer with a V1Sn vacancy change to a half-metal. V1Sn vacancy and V1Sn+1Se vacancy induce moments 4 and 2 μB, respectively. Mo-doped 1T-SnSe2 monolayer is a magnetic semiconductor with 2μB moment. Defect systems enhance the absorption efficiency of the solar energy. Defects study provides a promising platform for optoelectronic device applications.