Effect of nitrogen sputtering pressure on the electronic properties of LiPON solid-state electrolyte

Abstract

This study focuses on optimizing the sputtering deposition parameters to grow a LiPON solid-state electrolyte. Specifically, this study examines the impact of nitrogen deposition pressure on the electronic properties of LiPON solid-state electrolytes. Through a combination of scanning electron microscope analysis, X-ray diffraction studies, and chemical spectroscopy techniques, the study found that high nitrogen deposition pressure (20 mTorr) results in the formation of a discharge space with high-species concentration that reduces the mean free path of the ejected Li₃PO₄ target atoms. This leads to the growth of low-thickness films ($t=107 nm$) that lack nitrogen content and have a high-energy bandgap (${E}_{g}=4.69 eV$). On the other hand, low nitrogen deposition pressure (5 mTorr) results in the formation of a discharge space with low-species concentration that allows for the growth of thicker sputtered films ($t=315 nm$) with the correct stoichiometry of the LiPON phase. This leads to a lower energy bandgap (${E}_{g}=4.51 eV$).

Graphical abstract