Electrochemical Control of Copper Intercalation into Nanoscale BiSe.

Intercalation of exotic atoms or molecules into the layered materials remains an extensively investigated subject in current physics and chemistry. However, traditionally melt-growth and chemical interaction strategies are either limited by insufficiency of intercalant concentrations or destitute of accurate controllability. Here, we have developed a general electrochemical intercalation method to efficaciously regulate the concentration of zerovalent copper atoms into layered BiSe, followed by comprehensive experimental characterization and analyses. Up to 57% copper atoms (CuBiSe) can be intercalated with no disruption to the host lattice. Meanwhile the unconventional resistance dip accompanied by a hysteresis loop below 40 K, as well as the emergence of new Raman peak in CuBiSe, is a distinct manifestation of the interplay between intercalated Cu atoms with BiSe host. Our work demonstrates a new methodology to study fundamentally new and unexpected physical behaviors in intercalated metastable materials.