Description
Monolayer tetragonal CoSe is a cobalt-based analogue of monolayer FeSe and has recently been reported to show interface-induced superconductivity on redox-modified SrTiO₃. Here, we use ARPES to investigate the electronic structure of monolayer CoSe grown on FeOₓ-modified SrTiO₃. The main tetragonal CoSe band structure is preserved compared with CoSe/STO. However, the Γ-centered electron pocket shrinks, whereas the X-centered hole pocket expands, as further supported by MDC analysis. These changes indicate a hole-doping trend induced by the FeOₓ-modified interface. Our results demonstrate that FeOₓ interface engineering provides an effective route to tune the electronic structure of monolayer CoSe and may be closely related to the emergence of superconductivity in CoSe-based heterostructures.
