Reversible Potassium Intercalation in Blue Phosphorene-Au Network Driven by an Electric Field.

Foreign atom intercalation into an interface alters the strength of interlayer interaction and leads to the novel types of desirable properties. Here, we report an investigation via scanning tunnelling microscopy (STM) and scanning tunnelling spectroscopy (STS) of reversible potassium (K) intercalation in the blue phosphorene (blueP)-Au network that can be locally induced by an external electric field. The unique structure of the blueP-Au network provides large space in its pores for the intercalation and deintercalation process. The X-ray photoemission spectroscopy results reveal that the intercalated K atoms are bonded with Au atoms in substrate, which weakens the interaction between the blueP-Au network and Au(111). The STS and angle-resolved photoemission spectroscopy results indicate that the electronic properties of the blueP-Au network have been modulated after the K intercalation. Such reversible intercalation and deintercalation transitions in the blueP-Au network are relevant for the design of the nanoelectronic devices as well as for its application in K-ion batteries.