Designer strain distributions in a two-dimensional semiconductor

The bright emission from thick flakes makes gallium selenide a fantastic material for understanding the relationship between local strain and optical response. Here, we investigate complex strain distributions by transferring gallium selenide flakes onto nanostructures patterned in close proximity, enabling the study of a variety of strain distributions, such as uniaxial, biaxial, and triaxial strain within a single flake. Our findings reveal that finite strain distributions and resulting bandgap shifts occur in regions of gallium selenide suspended between closely-spaced nanostructures, in good agreement with strain distributions simulated using finite element analysis. This research paves the way for designer strain distributions and tailorable nanophotonic behavior in two-dimensional materials.