Local Strain Engineering in Atomically Thin MoS₂

Abstract

Controlling the bandstructure through\nlocal-strain engineering\nis an exciting avenue for tailoring optoelectronic properties of materials\nat the nanoscale. Atomically thin materials are particularly well-suited\nfor this purpose because they can withstand extreme nonhomogeneous\ndeformations before rupture. Here, we study the effect of large localized\nstrain in the electronic bandstructure of atomically thin MoS₂. Using photoluminescence imaging, we observe a strain-induced\nreduction of the direct bandgap and funneling of photogenerated excitons\ntoward regions of higher strain. To understand these results, we develop\na nonuniform tight-binding model to calculate the electronic properties\nof MoS₂ nanolayers with complex and realistic local strain\ngeometries, finding good agreement with our experimental results.