Toward lateral heterostructures with two-dimensional MoX2H2 (X = As, Sb)

Abstract

The development of two-dimensional (2D) lateral heterostructures (LHs) with the powerful tunability of electronic properties will be of great realistic significance for next-generation device applications. Herein, we report the novel 2D MoX₂ and MoX₂H₂ (X = As or Sb) monolayer materials with excellent stability. Using first-principles calculations, we demonstrated that 2D MoX₂ layers possess the metallic characteristic while the full surface hydrogenation effect would play a role in stabilizing the 2D lattices and lead to band gap openings of 0.83 and 0.50 eV for the 2D MoAs₂H₂ and MoSb₂H₂, respectively. In addition, our results suggest that the 2D MoAs₂H₂ and MoSb₂H₂ can serve as the ‘building blocks’ to construct the seamless LHs exhibiting excellent thermal and dynamical stability. The obtained nL-MoAsSb LHs enable the fully tunable band gap engineering behavior with linear tendency as a function of the width of the in-plane components. The phase transition from direct to in-direct band gap was also confirmed in the LHs as the crucial value of n = 3. In view of the type-II band alignment and efficient carrier separation in nL-MoAsSb, the predicted MoX₂H₂ and nL-MoAsSb LHs not only highlight the promising candidates for 2D pristine materials, but also paves the way for the realization of practical integrating device applications.