Size-Dependent Phase Transition in Ultrathin Ga2O3 Nanowires

Gallium oxide (Ga2O3) has attractedextensiveattention as a potential candidate for low-dimensional metal-oxide-semiconductorfield-effect transistors (MOSFETs) due to its wide bandgap, controllabledoping, and low cost. The structural stability of nanoscale Ga2O3 is the key parameter for designing and constructinga MOSFET, which however remains unexplored. Using in situ transmissionelectron microscopy, we reveal the size-dependent phase transitionof sub-2 nm Ga2O3 nanowires. Based on theoreticalcalculations, the transformation pathways from the initial monoclinic beta-phase to an intermediate cubic beta-phase and then backto the beta-phase have been mapped and identified as a sequenceof Ga cation migrations. Our results provide fundamental insightsinto the Ga2O3 phase stability within the nanoscale,which is crucial for advancing the miniaturization, light weight,and integration of wide-bandgap semiconductor devices.

Automated summary

This study reveals the size-dependent phase transition of sub-2 nm Ga2O3 nanowires using in situ transmission electron microscopy, providing crucial parameters for designing and constructing metal-oxide-semiconductor field-effect transistors.