【Epitaxy Papers】Effects of Nb and Nb-H Co-doping on the Electrical Properties of β-Ga₂O₃

      Researchers from the Beijing University of Technology have published a dissertation titled "Effects of Nb and Nb-H Co-doping on the Electrical Properties of β-Ga₂O₃" in Vacuum.

Abstract

      Nb and H co-doped Ga₂O₃ thin films were deposited on silicon (Si) and quartz substrates by RF magnetron sputtering, followed by a post-deposition annealing process. The study elucidated the synergistic effects of Nb and H doping on β-Ga₂O₃ formation. Nb doping promoted nucleation and growth, reduced grain boundary defects, suppressed non-radiative recombination, stabilized Ga³⁺, and inhibited oxygen vacancy (O_V) formation. Concurrently, H passivated intrinsic O_V by forming neutral complexes, thereby lowering active O_V concentration. This dual doping strategy significantly enhanced electrical properties: carrier mobility increased from 1.6 to 18.9 cm²·V^-1·s^-1. Consequently, the Si/Nb-H-Ga₂O₃/Au MSM photodetector exhibited dramatically improved performance, with a photo-to-dark current ratio of 18.85 and a responsivity of 0.812 A/W at 20 V-representing 54-fold and 10-fold enhancements over the pristine Ga₂O₃ device, respectively. This work demonstrates the potential of Ga₂O₃ for developing high-power and high-efficiency electronic devices.

DOI：

https://doi.org/10.1016/j.vacuum.2025.115043