Valence Band Offsets of LiPON∕LiCoO2 Hetero-Interfaces Determined by X-ray Photoelectron Spectroscopy

Abstract

Interfaces within Li-ion batteries are of interest with respect to stability and transfer resistance. In this paper, we investigated LiPON/LiCoO2 hetero-interfaces formed at room temperature (RT) and 200°C using X-ray photoelectron spectroscopy (XPS). The valence band offsets at the two interfaces were determined to be 1.15 eV and 0.65 eV, respectively. The difference in valence band offsets can be related to differing valence band edges in the LiPON, which exhibits a different chemical structure when deposited at higher temperature. In the future, such type of investigations should prove useful to understand the charge transfer at such interfaces in more detail.