The Influence of polymorphism on the electronic structure of Ga₂O₃

New wide and ultra wide band gap materials are necessary to develop more advanced generations of power electronic devices, ultimately improving their energy-efficiency and reliability. Ga₂O₃ is an interesting alternative to established materials such as SiC and GaN triggering renewed interest in its fundamental properties. In this work, three polymorphs of Ga₂O₃ are investigated using X-ray diffraction, soft and hard X-ray photoelectron and absorption spectroscopy, and ab initio theoretical approaches to gain insights into their structure–electronic structure relationships. The polymorphism of Ga₂O₃ and the related differences in local coordination environments are shown to affect both core levels as well as valence and conduction electronic structure. By combining state-of-the-art materials characterisation and electronic structure theory this work provides detailed insights into how tuning the structure of Ga₂O₃ results in differences in the electronic structure. Ultimately, the fundamental understanding of this relationship enables targeted tuning of materials properties which help to move towards integrating Ga₂O₃ in future power electronic device generations.