Co-Doped ErFeO₃ for Dual-Band Laser Absorption with High-Temperature Stability

The development of multi-band laser suppression materials has been driven by the limitations of single-band laser suppression materials. Inorganic ceramic materials, compared with organic laser suppression materials, photonic crystals, and metamaterials, offer significant advantages in fabrication methods and environmental stability. In this study, Co³⁺ ions, with relatively higher electronegativity, were introduced to substitute some Fe ion sites in ErFeO₃. This substitution caused distortion in the crystal structure, reduced the unit cell volume, and altered the band structure. As a result, the band gap was reduced compared with that of ErFeO₃, and the unique energy level transitions of Er ions were activated. This led to dual-band laser suppression with reflectances of 22.16% at 1064 nm and 35.63% at 1540 nm. Furthermore, after high-temperature testing at 1100 °C in air, the laser absorption performance could still be maintained with the intensity retention above 95%. This unique strategy for improving the band structure provides significant potential for applications in laser suppression.