Instability of nanoribbons on concave substrates

The instability of nanoribbons plays a key role in fields such as sensors, photovoltaic devices, energy storage, etc., thus attracting significant attentions of both scientific and industrial communities. However, the instability behavior of nanoribbons on non-flat substrates remains unclear, which hinders the design and development of related nanodevices. Herein, the instability behavior of nanoribbons on a concave spherical substrate is explored by molecular dynamics simulation and theoretical analysis. It is found that the length of short side of nanoribbon is the key parameter dominating critical wrinkling. The instability behavior can be well tuned through adopting suitable length of short side, substrate's radius and adhesion energy. Furthermore, possible strategies of inhibiting instability for nanosheets on concave substrates, i.e., reducing its size below the critical length or introducing splicing structures, are proposed and validated. The present findings should be of significant importance for improving instability mechanics of two-dimensional materials and providing guidance for the design and fabrication of various nanodevices.