Robust room-temperature ferroelectricity in the wide-bandgap semiconductor Ga₂O₃

For decades, the integration of power handling and nonvolatile memory has been fundamentally impeded by the incompatibility between wide-bandgap semiconductors and ferroelectric materials. We resolve this challenge by demonstrating robust room-temperature ferroelectricity in epitaxial metastable κ-Ga₂O₃, grown via industry-compatible metal-organic chemical vapor deposition, creating an intrinsically ferroelectric wide-bandgap semiconductor. Through systematic characterization including piezoresponse force microscopy, polarization hysteresis measurements, and positive up-negative down tests, we provide conclusive evidence of stable ferroelectric switching down to 5-nanometer thickness-exceeding conventional ferroelectric limits-via a unique octahedral-tetrahedral transformation. Ferroelectric tunnel junctions achieve giant tunneling electroresistance exceeding 10⁵. This fundamental discovery in a mainstream semiconductor challenges conventional materials paradigms and enables monolithic integration of power and memory functionalities on a unified platform.