Ab Initio Prediction of Novel Induced Stacking Phase Transition in Intercalated Bi₂Se₃ Heterostructures—Theory and Implications

In this work, we explore the role of metal intercalants in inducing a previously unknown structural phase transition in the van der Waals (vdW) material Bi₂Se₃, from the conventional ABC bulk stacking to an AAA stacking configuration. We perform a comprehensive ab intio study of the preferred intercalant locations, their relative stabilities, and their impact on the stacking order of the ground state structural phase, for a wide variety of metallic and semi-metallic intercalant species. The resulting intercalant-driven phase transition, combined with the diverse doping and magnetic properties of the intercalants, opens new opportunities for tuning the both the geometric and electronic properties of Bi₂Se₃ and potentially of other 2D vdW materials. Given Bi₂Se₃'s established performance as a thermoelectric material [1,2], we then investigate how different intercalant species can be utilized to independently optimize thermopower and thermal conductivity, thereby enhancing device efficiency, as quantified by the thermoelectric figure of merit (zT). Finally, we examine the interplay between our new stacking phase transition, the magnetic properties of the intercalants, and Bi₂Se₃’s topological surface states, and explore the potential to tune the stacking of near-critically intercalated Bi₂Se₃ through strain.

This work made use of the Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials (PARADIM), which is supported by the National Science Foundation under Cooperative Agreement No. DMR-2039380.

[1] A. M. Adam, A. Elshafaie, A. E. A. Mohamed, P. Petkov, and E. M. M. Ibrahim, Materials Research Express 5, 035514 (2018)
[2] X. Tang, Z. Li, W. Liu, Q. Zhang, and C. Uher, Interdisciplinary Materials 1, 88-115 (2022)