2018/05/06 by Martik Aghajanian, Aghajanian, Martik, Arash A. Mostofi +3 · 1 citation
Materials Science · #2D Materials and Applications #FOS: Physical sciences #Machine Learning in Materials Science #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · pdf · doi:10.48550/arxiv.1805.02167
openalex publication_date 2018/05/06 · openalex created_date 2018/05/17 · openalex updated_date 2026/07/28
Adsorbate engineering is a promising route for controlling the electronic properties of monolayer transition-metal dichalcogenide materials. Here, we study shallow bound states induced by charged adatoms on MoS2 using large-scale tight-binding simulations with screened adatom potentials obtained from ab initio calculations. The interplay of unconventional screening in two-dimensional systems and multivalley effects in the transition-metal dichalcogenide (TMDC) band structure results in a rich diversity of bound impurity states. We present results for impurity state wavefunctions and energies, as well as for the local density of states in the vicinity of the adatom which can be measured using scanning tunnelling spectroscopy. We find that the presence of several distinct valleys in the MoS2 band structure gives rise to crossovers of impurity states at critical charge strengths, altering the orbital character of the most strongly bound state. We compare our results to simpler methods, such as the 2D hydrogen atom and effective mass theory, and we discuss limitations of these approaches.