Multiple Charge Carriers Manipulation Toward Semiconductive Ceramic Nanocomposites for Corrosion-Resistant Electromagnetic Wave Absorption

The modulation of transport properties in ceramic-based semiconductors can be used to optimize the electromagnetic response mechanism and performance. A semiconductor ceramic foam interlayer wall (SCFW) is designed by a physical vapor deposition method. The interlayer structural SCFW is composed of semiconductor-insulator-semiconductor layers, incorporating a composite system of SiC, Al_4.8Si_1.2O_9.6, and Al₂O₃. Moreover, the hierarchical network structure of the foam interlayer wall is controlled by the pyrolysis-deposition kinetic process. Electrons and holes are transported through the heterojunctions between SiC and Al_4.8Si_1.2O_9.6, achieving effective charge relaxation. The Al₂O₃ matrix provides lightweight properties (density of 0.967 g cm⁻³), while the hierarchical network structure determines the excellent electromagnetic wave (EMW) absorption performance of the SCFW, with an effective bandwidth up to 14.8 GHz under electromagnetic response (minimum reflection loss RL_min = −50.6 dB). the SCFW has been proven to exhibit corrosion resistance and thermal insulation properties, with a thermal conductivity up to 0.025 W m⁻¹ K⁻¹. This study provides valuable insights into the structural design and dielectric property optimization of ceramic-based semiconductor nanocomposites, which leads to strong polarization loss, opening new avenues for the application of EMW absorbers, and the EMW absorption mechanism of ceramics.