The investigation of chemical interaction and energy level alignment at Bepp2/Fe65Co35 interface

In a bilayer system of Bepp2-FeCo, the element content variation and chemical states of the Bepp2-FeCo interface were investigated using X-ray and ultraviolet photoelectron spectroscopy with Ar ion etching. Chemical reaction was observed for Co and Fe with Bepp2 at the interface. Ultraviolet photoelectron spectroscopy results showed a downward energy shift of −1.0 eV at the interface. This behavior was attributed to the formation of an interface dipole layer. The hole injection barrier ΦpB was 2.0 eV, and the electronic injection barrier ΦnB was 0.6 eV. Moreover, only as the FeCo thickness is less than 3 nm, an uniaxial anisotropy can be induced on the organic layer with the investigation of magnetic optical Kerr effect, this can be used as a multi-function devices.