Multispectral ErBO₃@ATO porous composite microspheres with laser and electromagnetic wave compatible absorption

The high-speed advances in electromagnetic (EM) wave and laser detection technology have accelerated the innovation of absorbing materials toward specific multi-band compatibility. It is difficult to achieve dual absorption of EM waves and near-infrared lasers by absorbing materials in a single frequency band; the design of high-performance laser-EM wave multi-band compatible absorbing materials is imminent. Herein, ErBO₃@ATO (erbium borate/antimony-doped tin oxide) porous composite microspheres with an average size of 15–20 μm are produced solvothermal method and self-assembly, which exhibit excellent laser-EM wave compatible absorption. The porous structure on the surface of ErBO₃ microspheres provides heterogeneous nucleation sites for ATO particle deposition. The minimum reflectivity of the composite for 1.06 and 1.54 μm lasers is 9.59% and 4.79%, which is 0.57% and 3.78% lower than those of pure ATO particles, respectively. The composites containing 70 wt% porous ErBO₃@ATO reveal the minimum reflection loss (RL) value of − 31.6 dB, and an effective absorption band width reaches 2.08 GHz at 2.5 mm thickness. The mechanism of near-infrared laser and EM wave compatible absorption is the synergistic effect of the energy level transition of ErBO₃ and the dielectric loss of ATO, coupled with the large surface area and porous structure of the microspheres. Therefore, the designed porous ErBO₃@ATO composite microspheres can be an attractive choice for lasers and EM wave high-quality compatible absorption. Graphical abstract: [Figure not available: see fulltext.]