Controlling Size-Induced Phase Transformations Using Chemically Designed Nanolaminates

By dimensionally constraining crystalline layers in a non‐epitaxial intergrowth, nanocrystal ensembles with well‐defined and precisely controlled size are prepared. Synchrotron X‐ray diffraction, electron microscopy, and density functional theory show that a size‐induced second‐order structural transition allows the crystal structure of a layered semiconductor (SnSe) to be continuously tuned by controlling the thickness of the individual layers.