Intrinsic Ferroelectricity Confirmed in Gallium Oxide at Room Temperature, Paving Way for High-Power Memory Integration

A research team led by Professor Wu Zhenping from the School of Physical Science and Technology at Beijing University of Posts and Telecommunications, in collaboration with The Hong Kong Polytechnic University, Nankai University, and other institutions, has achieved a major breakthrough in wide bandgap semiconductor research—experimentally verifying the intrinsic ferroelectricity of gallium oxide (Ga₂O₃) at room temperature. The findings were published in the journal Science Advances.

As a "star material" among ultra-wide bandgap semiconductors, gallium oxide holds great promise for high-power electronic devices and solar-blind detection due to its bandgap of approximately 4.8 eV and excellent breakdown resistance. However, enabling it to possess memory storage functionality (ferroelectricity) similar to a "USB drive" has long been a scientific challenge. Wide bandgap semiconductors require a "rigid" crystal structure to ensure electrical stability, while ferroelectric materials rely on "flexible" atomic displacement to achieve information storage—a fundamental structural contradiction long considered difficult to reconcile.

Addressing this challenge, the research team employed industrially compatible metal-organic chemical vapor deposition (MOCVD) technology to successfully grow high-quality pure-phase epitaxial κ-Ga₂O₃ thin films. Through precise experimental characterization, the team observed stable ferroelectric switching, achieving devices with an on/off ratio exceeding 10⁵ and endurance over 10⁷ cycles. First-principles calculations and atomic-scale imaging further revealed the microscopic mechanism: polarization switching is realized through cooperative structural distortion between GaO₄ tetrahedra and GaO₆ octahedra, achieving ferroelectric functionality without breaking chemical bonds.

This discovery confirms that wide bandgap semiconductor characteristics and ferroelectricity can coexist harmoniously in a single material, providing clear experimental evidence that resolves a long-standing academic debate. More importantly, the research opens new pathways for semiconductor technology—a single material platform (gallium oxide) can simultaneously meet the demands of high power, high voltage tolerance, and non-volatile memory. This means that future devices could achieve both power processing and information storage functions within the same material, offering a novel material foundation and design paradigm for multifunctional integrated devices in extreme environments such as smart grids, electric vehicles, and aerospace applications.