AVS 54th International Symposium | |
Thin Film | Thursday Sessions |
Session TF1-ThA |
Session: | Photovoltaics, Fuel Cells, and Alternative Energy Materials and Applications |
Presenter: | S. Thevuthasan, Pacific Northwest National Laboratory |
Authors: | S.V.N.T. Kuchibhatla, Pacific Northwest National Laboratory P. Nachimuthu, Pacific Northwest National Laboratory C.M. Wang, Pacific Northwest National Laboratory V. Shutthanandan, Pacific Northwest National Laboratory M.H. Engelhard, Pacific Northwest National Laboratory L.V. Saraf, Pacific Northwest National Laboratory S. Thevuthasan, Pacific Northwest National Laboratory S. Seal, University of Central Florida |
Correspondent: | Click to Email |
Mesoscopic fast ion conduction in nanometer-scale planar heterostructures is gaining attention from researchers in the field of solid-state ionic conducting devices. One such device and the most popular among alternative energy sources is solid oxide fuel cell (SOFC). In SOFCs oxygen ions should be effectively conducted from cathode to anode through an electrolyte. Hence, it is quite essential to develop electrolyte materials that offer low and intermediate temperature ionic conductivity. Currently, yttria stabilized zirconia (YSZ) is the most widely used electrolyte, but the need for temperatures in the range of 800oC-1000oC imposes various restrictions in expanding the SOFC technology. Samaria doped ceria has been extensively studied as an alternative to YSZ at intermediate temperatures. Structural configuration of these thin films plays a major role in oxygen ionic conduction and we have initiated several studies to understand the influence of structure and chemistry of these thin films on oxygen ionic conductivity. We have synthesized high quality single- and poly- crystal films of Sm doped ceria(SDC) and Sc stabilized zirconia (ScSZ) using oxygen plasma assisted molecular beam epitaxy and characterized those using several surface and bulk sensitive techniques. The effect of growth temperature on the domain structure and the ionic conductivity are features of interest in the research associated with single- and poly- crystal SDC films. It appears that the strain, chemistry and structure at the interface play a role on ionic conduction in the SDC and ScSZ multi-layer films. The enhancement in oxygen ionic conductivity through some of these films at low temperatures are encouraging.