Semiconductor Heterostructure (SFT-SnO₂) Electrolyte with Enhanced Ionic Conduction for Ceramic Fuel Cells

Electronicconduction inhibition, heterostructure construction,constituting built-in electric field (BIEF), and the generation ofan energetically more active region in the lattice and at the interfaceare ways to increase the ionic conductivity (sigma(i))of electrolyte materials for ceramic fuel cells (CFCs). The conductionof ions and stoppage of e(-) conductivity are of utmostimportance in semiconductor-based electrolytes. Type-II heterojunctioncan be synthesized to improve fuel cell performance by increasingionic conductivity. SFT (SrFe0.3Ti0.7O3)-SnO2 p-n heterojunction was produced bycombining p-type SFT and n-type SnO2 semiconductors. Theresulting SFT-SnO2 heterostructure unveiled a highionic conductivity of 0.18 S/cm and an open-circuit voltage (OCV)of 1.04 V, contributing to a remarkable power output of 805 mW/cm(2) at a low operating temperature of 520 degrees C. High ionicconductivity and efficient fuel cell performance are attributed toa synergistic interaction between the SFT/SnO2 heterojunctionand BIEF. Heterojunction production between SFT and SnO2 was confirmed by numerous characterization techniques (X-ray diffractometer(XRD), scanning electron microscopy (SEM), high-resolution transmissionelectron microscopy (HR-TEM), UV-visible, ultraviolet photoelectronspectroscopy (UPS), X-ray photoelectron spectroscopy (XPS)). The SFT/SnO2 junction valence band deviation and energy band structurewere also validated. Our research shows that the constructed heterostructureSFT-SnO2 is an effective and efficient electrolytematerial for future fuel cell technology.