【Substrate Papers】Electron Scattering and Hopping Conduction Mechanisms in n-type β-Ga₂O₃

      Researchers from the Shimane University have published a dissertation titled " Electron Scattering and Hopping Conduction Mechanisms in n-type β-Ga₂O₃" in Journal of Electronic Materials.

Abstract

      Experimental data of temperature-dependent Hall-effect measurements on n-type β-Ga₂O₃ samples have accumulated rapidly over the past decade. Simultaneous fits to the reported data of the temperature dependence of the electrical conductivity, the Hall coefficient, and the Hall mobility on variously grown n-type β-Ga₂O₃ samples have been performed taking into account various electron scattering mechanisms and hopping conduction mechanisms. Besides shallow hydrogenic donor states between which hopping conduction occurs, an additional deep level with ionization energy of about 50 meV is found in almost all the investigated samples. In addition to the dominant scattering mechanisms due to polar optical phonon scattering at high temperatures and ionized-impurity scattering at low temperatures, significant effects of acoustic phonon scattering and neutral-impurity scattering due to both the shallow and deep donor levels have been revealed for free-electron conduction in the intermediate temperature range. In the samples with small concentrations of shallow donors, nearest-neighbor hopping is found to dominate at low temperatures, whereas the dominance of Mott-type variable-range hopping is found for heavily doped samples. Regarding the ionization energy of the shallow hydrogenic donor level, a linear relation of E_D = E_D0 − α₀N_A^1/3, where E_D0 = 40 meV and α₀ = 4.3 × 10⁻⁵ meV cm, has been obtained, with N_A denoting the concentration of compensating acceptors.

DOI：

https://doi.org/10.1007/s11664-025-12087-z