Exploring Anisotropic Carrier Transport in WSe₂-WTe₂ Superlattices: A Computational Study

Superlattice structures offer distinct benefits in modern semiconductor technology, enabling the development of a deeper understanding of their sublayer arising from the interfaces. However, the advancement of large-scale applications encounters additional concerns, such as the stability and performance of the superlattice. In this study, we employ density functional theory calculations combined with the Boltzmann transport theory to comprehensively analyze the electronic structural and transport properties of the hexagonal phase of WSe₂ and the WSe₂-WTe₂ superlattice for their applications in carrier transport fields. Previous studies showed that longitudinal acoustics phonon limited carrier mobility determined by deformation potential theory (DPT) often compromises the accuracy and overestimates the relaxation time by 2 orders. Herein, we conduct an in-depth analysis of band structural and transport properties, addressing the aforementioned inconsistency by exclusively incorporating scattering from longitudinal optical phonons to accurately compute mobility using the Fröhlich interaction. Our findings reveal a significant enhancement in mobility for both electrons and holes in the WSe₂-WTe₂ superlattice, reaching 545 and 476 cm² V^-1 s^-1, respectively, compared to 104 and 132 cm² V^-1 s^-1 for WSe₂, which suggests that this superlattice is a promising material for electronics and transport applications.