A thin-film yttrium-doped barium zirconate comprised of two distinct layers with different porosity was fabricated by pulsed laser deposition method for a low-temperature solid oxide fuel cell electrolyte to enhance electrode reactions and suppress electric short-circuit problem simultaneously. At 250 degrees C, the peak power density of bi-layer electrolyte fuel cell was similar to 2 mW/cm(2), which is similar to 56% higher than that of single-layer electrolyte fuel cell due to significant reduction of cathodic activation loss. A set of materials characterizations revealed that the differences in compositions and micro-structures at the electrolytes accounts for the improved performance. (C) 2013 Elsevier B.V. All rights reserved.