Phase Evolution in La-Alloyed β-Ga2O3 Nanofibers: Experimental and DFT Simulation Insights

Abstract

La-alloyed β-Ga2O3 nanofibers with varying La concentrations (0, 1, 5, and 10 at. %) are successfully synthesized using the electrospinning method to investigate the effects of incorporating La on phase formations. At La 1 at. % alloying, the polycrystalline β-Ga2O3 phase remains stable, indicating that this concentration is within its solubility limit. However, higher La alloying levels (5 and 10 at. %) lead to the formation of additional phases, including La2O3, Ga3La5, La4Ga2O5, cubic La2O5, and orthorhombic LaGaO3. Notably, when increasing the La concentration, the nonoxide metallic compound La3Ga5 is observed, likely due to enhanced Ga-La interactions. Density functional theory (DFT) simulations confirm that La3Ga5 has metallic properties, which could potentially improve the electrical performance of Ga2O3-based devices. Furthermore, DFT simulations predict the formation, phase stability, and structure of La-based precipitates, offering valuable insights into the alloying behavior and material properties of Ga2O3. These findings suggest possibilities for enhancing the functionality of Ga2O3 semiconductors in electronic applications.