Mist Chemical Vapor Deposition of Ultrawide Bandgap p‐LiGa ₅ O ₈ on AlN and Determination of the Band Offsets at the LiGa ₅ O ₈ /AlN Interface

The epitaxial growth of LiGa ₅ O ₈ —a recently identified ultrawide bandgap (UWBG) semiconductor is reported with room‐temperature p‐type conductivity‐on aluminum nitride‐on‐sapphire templates using mist chemical vapor deposition. The resulting LiGa ₅ O ₈ thin films exhibit hole concentrations of (5 × 10 ¹⁷ –1 × 10 ¹⁸ cm ⁻³ ) and mobilities between 1 and 4 cm ² V ⁻¹ s ⁻¹ . Scanning electron microscopy and atomic force microscopy confirm decent surface morphology, while cross‐sectional scanning transmission electron microscopy (STEM) and X‐ray diffraction reveal a spinel cubic phase oriented along the [111] growth direction. Elemental mapping via STEM–energy‐dispersive x‐ray spectroscopy (EDX) indicates negligible oxidation at the LiGa ₅ O ₈ /AlN interface. Additionally, X‐ray photoelectron spectroscopy measurements confirm a type‐I band alignment, which is important for designing heterostructures for device applications. Overall, results from this work provide knowledge base of LiGa ₅ O ₈ as a promising UWBG oxide semiconductor for high‐power electronics and deep ultraviolet optoelectronic device applications.