Mechanical exfoliation of single-crystalline spin-crossover molecular crystal

Mechanical exfoliation of two-dimensional van der Waals atomic crystals has led to significant scientific progress and developments in next-generation nanodevice technology. This talk reports the mechanical exfoliation of a novel spin-crossover molecular crystal with strongly anisotropic intermolecular interactions. Monocrystalline flakes of molecular crystal down to monolayer thickness remain chemically and structurally intact as verified by Raman spectroscopy and atomic force microscopy. Temperature-dependent optical measurements characterize properties of the spin transition as a function of the layer numbers. Additionally, we build 2D inorganic-organic heterostructures and examine the interlayer coupling. Our results establish a new molecular building block for the library of two-dimensional van der Waals materials.