Spin-crossover nanoparticles anchored on MoS 2 layers for heterostructures with tunable strain driven by thermal or light-induced spin switching.

In the past few years, the effect of strain on the optical and electronic properties of MoS ₂ layers has attracted particular attention as it can improve the performance of optoelectronic and spintronic devices. Although several approaches have been explored, strain is typically externally applied on the two-dimensional material. In this work, we describe the preparation of a reversible 'self-strainable' system in which the strain is generated at the molecular level by one component of a MoS ₂ -based composite material. Spin-crossover nanoparticles were covalently grafted onto functionalized layers of semiconducting MoS ₂ to form a hybrid heterostructure. Their ability to switch between two spin states on applying an external stimulus (light irradiation or temperature change) serves to generate strain over the MoS ₂ layer. A volume change accompanies this spin crossover, and the created strain induces a substantial and reversible change of the electrical and optical properties of the heterostructure.
(© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)