Noncovalently functionalization of Janus MoSSe monolayer with organic molecules

Abstract

Because the crystal structure of Janus MoSSe is between from MoS 2 and MoSe 2 , and the Janus MoSSe probably exhibited to outstanding characteristics difference from MoS 2 and MoSe 2 . Adsorption of organic molecules is a prospective and effective pattern to modify the optoelectronic properties of 2D materials . For this purpose, the optical and electronic characteristics of organic molecules adsorbed Janus MoSSe monolayer were discussed by the first principles calculations. The results indicate that p -doped Janus MoSSe can be obtained by molecular doping with tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE), whereas n -doped Janus MoSSe can be realized by doping with tetrathiafulvalene (TTF). Importantly, a dipole moment is produced between Janus MoSSe and organic molecule, and the dipole moment can to a great extent alter the work function values of Janus MoSSe ranged from 3.76 eV to 6.17 eV. Interestingly, the impurity band near the Fermi level appears in the band structures of Janus MoSSe after different organic molecules adsorption, which demonstrates that electron is more prone to transition. Furthermore, Adsorption of organic molecules on Janus MoSSe can significantly expand its optical absorption spectrum in the visible light region. This study gives a theoretical guidance for the fabrication of Janus MoSSe-based photovoltaics nanodevices . • Effective p-type doping of MoSSe can be realized by adsorption of TCNE and TCNQ molecules, while n-doped MoSSe can be obtained by adsorption of TTF molecule. • A dipole moment is formed between organic molecule and Janus MoSSe, and this dipole moment can significantly tune the work function values of Janus MoSSe. • Adsorption of organic molecules on Janus MoSSe can significantly expand its optical absorption spectrum in the visible light region.