Strain modulation using defects in two-dimensional MoS2

We investigate the nature of strain in MoS2 and correlate it to defect types and densities, while systematically assessing the tolerance of this low dimensional material to He and Au ion irradiations. Through a series of theoretical predictions and experimental observations, we establish the onset of the crystalline-to-amorphous transition in MoS2 and identify sulfur vacancies as the most favorable defects introduced during irradiation. We note the presence of both tensile and compressive strains, which depend on the types of defects introduced into the lattice and vary with increasing fluence. The results show that defects can be used to tune strain in two-dimensional materials and provide an exciting pathway for using external stimuli to control properties of low dimensional materials.