AVS 63rd International Symposium & Exhibition
    Applied Surface Science Wednesday Sessions
       Session AS+SS-WeM

Paper AS+SS-WeM13
Energy Storage Materials – Investigating the Surface

Wednesday, November 9, 2016, 12:00 pm, Room 101B

Session: Applications where Surface Analysis is Your Only Hope
Presenter: Jonathan Counsell, Kratos Analytical Limited, UK
Authors: J.D.P. Counsell, Kratos Analytical Limited, UK
S.J. Coultas, Kratos Analytical Limited, UK
C.J. Blomfield, Kratos Analytical Limited, UK
C. Moffitt, Kratos Analytical Limited
Correspondent: Click to Email
Lithium ion batteries are commonly found in home electronic equipment. In recent times there have been significant efforts to improve the durability, cycle time and lifetime decay of the batteries and in particular the electrode/electrolyte material. Novel materials have been developed to also increase the energy storage density. Lithium phosphorus oxynitride (LiPON) has become the most commonly used solid electrolyte thin-film in energy storage devices. Obviously due to the widespread use of this material there is significant interest in understanding the characteristics and properties with a view towards optimisation.

Here we apply XPS and UPS to explore both the surface and bulk properties of several LixPOyNz surfaces prepared via atomic layer deposition ALD [1]. The distribution of elements below the surface is explored via ion and angular-resolved depth profiling methods. This technique has been used extensively across a broad range of applications however the damage caused by impinging ions on the structure of the analysis material has always been a concern for the analyst. More recently Argon gas cluster ion sources have been employed to reduce the chemical damage of organic materials and broaden the range of materials amenable to this type of analysis. Here we extend the application of cluster ions beyond organics to inorganic oxides. Herein we discuss how, with the use of Ar250-3000+ ions, where the energy per atom can be 2.5-40 eV, it is possible to obtain more accurate information regarding the true nature of the LiPON thin-film. A comparison is made with conventional monatomic depth profiles in particular the differences in stoichiometry obtained with the two ion sources. Ion implantation is also discussed as are the unfortunate chemical effects of carbon deposition from organic cluster ions. We will demonstrate how the analyst can now confidently depth profile through inorganic metal oxide thin-films without the worry of reduction or preferential sputtering.

[1] Alexander C. Kozen, Alexander J. Pearse, Chuan-Fu Lin, Malachi Noked, Gary W. Rubloff, DOI: 10.1021/acs.chemmater.5b01654