An optoelectronic material with a spatially varying bandgap that is tunable is highly desirable for use in photovoltaics, photocatalysis and photodetection. Elastic strain has the potential to be used to achieve rapid and reversible tuning of the bandgap. However, as a result of plasticity or fracture, conventional materials cannot sustain a high enough elastic strain to create sufficient changes in their physical properties. Recently, an emergent class of materials-named 'ultrastrength materials'-have been shown to avoid inelastic relaxation up to a significant fraction of their ideal strength. Here, we illustrate theoretically and computationally that elastic strain is a viable agent for creating a continuously varying bandgap profile in an initially homogeneous, atomically thin membrane. We propose that a photovoltaic device made from a strain-engineered MoS2 monolayer will capture a broad range of the solar spectrum and concentrate excitons or charge carriers. C1 [Feng, Ji] Peking Univ, Sch Phys, Int Ctr Quantum Mat, Beijing 100871, Peoples R China. [Qian, Xiaofeng; Huang, Cheng-Wei; Li, Ju] MIT, Dept Nucl Sci & Engn, Cambridge, MA 02139 USA. [Qian, Xiaofeng; Huang, Cheng-Wei; Li, Ju] MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. [Li, Ju] Xi An Jiao Tong Univ, State Key Lab Mech Behav Mat, Xian 710049, Peoples R China. [Li, Ju] Xi An Jiao Tong Univ, Frontier Inst Sci & Technol, Xian 710049, Peoples R China.