Optoelectronic Crystal of Artificial Atoms in Strain-Textured MoS$_{2}$

The atomically thin semiconductor MoS$_2$ possesses exceptional strength and a strain-tunable band gap. When subjected to biaxial elastic strain, monolayer MoS$_2$ can embed wide band gap variations overlapping the visible spectrum, with calculations showing the modified electronic potential emanating from point-induced tensile strain perturbations mimic the Coulomb potential in a mesoscopic atom. We have realized and confirmed this ``artificial atom'' concept via capillary-pressure-induced nanoindentation of monolayer MoS$_2$ from a tailored nanostructure. We demonstrate that a synthetic lattice of these building blocks forms an optoelectronic crystal capable of broadband light absorption and efficient funneling of photogenerated excitons to points of maximum strain at the atom centers. Such 2D semiconductors with spatially textured band gaps represent a new class of materials which may find applications in next-generation optoelectronics or photovoltaics.