Controlled and unified Schottky barriers mediated by amorphization design toward ultrathin high-performance microwave absorption

Schottky contacts at (semi)metal/semiconductor heterointerfaces, known for their prominent spatial charge separation effect, have attracted increasing interest for microwave absorber (MAM) applications, but the inappropriate and non-uniform barrier heights between existing polycrystalline semiconducting and (semi)metallic components present a major challenge for achieving high-permittivity dielectric matching, a critical prerequisite for ultrathin high-performance MAMs. Here, we report an amorphization-mediated strategy to tailor Schottky contacts via an innovative intercalation-coprecipitation-annealing process. This yields amorphous TiO 2 (a-TiO 2 ) with isotropic nanostructures and a unified work function, interfacing intimately with large-area reduced graphene oxide (rGO) basal planes. Critically, amorphization suppresses the Schottky barrier height to < 0.2 eV via elevated oxygen vacancies, and eliminates barrier dispersion induced by crystallographic orientations. The resultant rGO/a-TiO 2 heterointerfaces enable high-permittivity dielectric matching, achieving controlled dielectric loss (tan δ e ) at enhanced permittivity ( ε ’), thereby overcoming impedance mismatch via curbing the difference between permittivity and permeability of the material effectively. When integrated with flaky carbonyl iron (FCI) to provide magnetic/dielectric synergy, the rGO/a-TiO 2 /FCI (RTF) nanocomposite can achieve first-class absorption (-79.51 dB) at ultrathin thicknesses (< 1.5 mm). This work demonstrates how amorphization engineering precisely modulates the magnitude and uniformity of Schottky barrier, opening pathways for ultrathin high-performance MAMs and other functional applications.