AVS 53rd International Symposium
    Thin Film Wednesday Sessions
       Session TF-WeA

Paper TF-WeA7
Fabrication and Fuel Cell Performance of Ultra-Thin Yttrium-Doped Barium Zirconate Films

Wednesday, November 15, 2006, 4:00 pm, Room 2022

Session: Thin Films for Energy Applications in Photovoltaics, Fuel Cells, Hydrogen Storage & Batteries
Presenter: J.H. Shim, Stanford University
Authors: J.H. Shim, Stanford University
T.M. Gür, Stanford University
F.B. Prinz, Stanford University
Correspondent: Click to Email
Acceptor-doped perovskites such as yttrium or gadolinium-doped barium cerate (BaCeO@sub 3@), strontium cerate (SrCeO@sub 3@) and barium zirconate (BaZrO@sub 3@) have been intensively studied as potential proton conducting electrolytes for fuel cells due to their high ionic conductivity for protons.@footnote 1@ However, instability in acidic gas environment such as carbon dioxide has limited practical usage of most of the doped cerates. Only yttrium doped barium zirconate (Y:BaZrO@sub 3@) has shown high proton conductivity combined with sufficient chemical stability.@footnote 2@ However, Y:BaZrO@sub 3@ is difficult to be densified using conventional sintering processes. This adversely affects their conductivity and mechanical strength.@footnote 3@ Furthermore, most Y:BaZrO@sub 3@ membranes that have been reported in the literature have been fabricated at thicknesses exceeding few tens of microns, which limits their use in low temperature applications because of its high area specific resistance (ASR). In this work, we report fabrication of nano-scale Y:BaZrO@sub 3@ films using an optimally-conditioned pulsed laser deposition technique. The thin films are prepared on single crystal magnesium oxide substrates or silicon nitride-buffered single crystal silicon wafers. Structural qualities of the film including crystallinity, density, and film composition are investigated using the X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and reflection (XRR) measurements. With the ultra-thin Y:BaZrO@sub 3@ membrane, we have fabricated fuel cells and measured the performance in terms of voltage-current relations. @FootnoteText@ @footnote 1@ Iguchi, S. et al., 2004 Fuel Cell seminar, Nov. 1-5, San Antonio, TX, USA (2004)@footnote 2@ Kreuer, K. D. Annual Review of Materials Research 33, 333-359 (2003)@footnote 3@ P. Babilo & S. M. Haile, J. Amer. Cer. Soc. 88, 2362-2368 (2005).