In this work, the electronic transport properties of unintentionally doped (UID) and tin-doped β-Ga₂O₃ homoepitaxial thin films grown by molecular beam epitaxy (MBE) are reported, with electron densities ranging from 3.2×10¹⁶ to 2.9×10¹⁹ cm^-3. The UID thin film with an electron density of 3.2×10¹⁶ cm^-3 exhibits an excellent room-temperature mobility of 125 cm²·V^-1·s^-1 and a peak mobility of 875 cm²·V^-1·s^-1 at 80 K, reaching the advanced standard of MBE-grown Ga₂O₃ thin films. Temperature-dependent Hall measurements were utilized to characterize the electronic transport properties of the homoepitaxial thin films, yielding a tin dopant activation energy of 76.2 meV. By fitting the scattering model, the electronic scattering properties of this series of homoepitaxial thin films were analyzed, revealing that ionized impurity (II) scattering from intrinsic defects and polar optical phonon (POP) scattering from Coulombic forces between cations and anions in the crystal limit the mobility growth at low and high temperatures, respectively.