Optoelectronic superlattices based on 2D transition metal dichalcogenides

Abstract

Optoelectronic superlattices are proposed based on two-dimensional transition metal dichalcogenides, which can be realized by periodically superimposed, interlaced, or alternate modulations of the gate voltage and the off-resonant right circularly polarized light. Owing to the huge band gap and spin–orbit coupling, the propagation of electrons through the gate tunable WSe2 superlattice under the optical field becomes highly valley-dependent, i.e., the transmission and conductance are suppressed for the K valley but enhanced remarkably for the K′ valley. Moreover, it is shown that the properties of the line-type resonant peaks are extremely sensitive to the valley and spin degrees of freedom, the period number of superlattice, and the mode of modulated external fields and can be further drastically adjusted by the width of the modulated region. This work may shed light on potential applications of the optoelectronic superlattices in the fields of valleytronics and spintronics.