Recent Developments in Alkali Metal Intercalation of Layered Transition Metal Dichalcogenides

The modification of layered transition metal dichalcogenides through intercalation is reviewed, with special emphasis on in situ intercalation with alkali metals. Experimental results obtained using photoelectron spectroscopy, low-energy electron diffraction, scanning tunneling microscopy and transmission electron microscopy are presented, and conclusions about the in situ intercalation process and the associated crystallographic and electronic structure changes are presented. It is stressed that various kinds of defects and disorders must be taken into account for a full understanding.