High UV Transparent Conductivity of SrMoO3 Thin Films

Abstract

The perovskite oxide SrMoO₃ has attracted significant attention for its potential applications in ultraviolet (UV) transparent conductors. Thus far, synthesizing high-quality epitaxial SrMoO₃ thin films by pulsed laser deposition (PLD) is usually under highly reducing (Ar or Ar-H₂ gas mixture) atmospheres. Here, we grew SrMoO₃ epitaxial films using the PLD technique at a base pressure below 1 × 10^–5 Pa without any gas supply to optimize their optical and electrical properties. By depositing these films on the (001) SrTiO₃, (001) LaAlO₃, and (001) MgO substrates, the as-grown SrMoO₃ films, with a nominal lattice mismatch in the range of −4.8 to +5.7% and a thickness of 20–60 nm, show prominent transparent conductivity in both visible and UV wavelengths. All the films exhibit metallic-like conductivity, with a room-temperature resistivity varying from 10 to 60 μΩ·cm. The resistivity increases with decreasing thickness. Notably, we can achieve extremely high transmittance, exceeding 80% for wavelengths ranging from 300 to 500 nm, and a low resistivity of approximately 20 μΩ·cm in SrMoO₃ films as thin as 20 nm. The excellent UV transparent conducting properties that are insensitive to the substrate type and film thickness make SrMoO₃ films a promising material for various photoelectronic devices and energy-harvesting applications.