Stable Correlated 4d² SrMoO₃ Films Epitaxially Coated on Al₂O₃ for Electromagnetic Shielding and Transparent Conductors

Abstract Correlated perovskites have attracted significant attention worldwide for their potential application in transparent conductors. However, most studies in this area have focused on single‐crystalline films grown on expensive perovskites. In this study, the transparent conducting properties of SrMoO₃ epitaxial films grown on Al₂O₃, the most commonly used substrate for optoelectronics, are investigated. The 45−80‐nm‐thick SrMoO₃ epitaxial films on ‐oriented Al₂O₃ exhibit low sheet resistance (< 50 Ω □⁻¹) at room temperature and high ultraviolet‐visible transmittances (> 60%), comparable with the values expected from single‐crystalline films. The highly conductive properties induced by two electrons in the outermost 4d orbitals guarantee a high electromagnetic shielding effectiveness of approximately 28.5 dB at 10 GHz in the X‐band. The SrMoO₃ films are thermally stable below 450 °C in air and 700 °C in vacuum. Taken together, these results indicate that SrMoO₃ epitaxial films grown on Al₂O₃ can be highly promising for optoelectronic applications in extreme environments.