High-Performance Reticular Porous Perovskite Coating with Wide-Spectrum Absorption for Photothermal Conversion

Good thermal shock resistance and high absorptivity in a wide spectral range, as the two key aspects of photothermal coating in high-temperature applications, are seldom realized simultaneously. Herein, it is reported that a reticular porous Ca-doped LaCrO 3 perovskite photothermal coating fabricated by a simple process presents excellent thermal shock resistance between 1200 °C and room temperature and optical absorptivity of ≈94% in the wavelength range of 0.3–14 μm. The high-temperature sintering after screen printing triggers significant variations in the microchemistry and microstructure of the Ca-doped LaCrO 3 coatings, and the experimental analyses and the first-principles calculation demonstrate that the appropriate doping of Ca 2+ causes lattice distortion, decreases the lattice parameters and bandgap, and effectively enhances interactions between the photon and carrier, resulting in the high optical absorptivity in the visible, near-, and mid-infrared ranges. The reticular porous microstructure and interfacial diffusion bonding between the coating and Al 2 O 3 substrate with a gradient transition layer contribute to the high-temperature thermal shock resistance. Herein, a novel way to fabricate a high-performance and low-cost photothermal conversion coating is provided, which presents a broad application prospect in energy harvesters and sensors.