Femtosecond pump-probe experiments in a transmission geometry were performed on Sn-doped n-type β-Ga₂O₃. With the pump and probe wavelengths below the bandgap, the differential transmission signal was determined by the free electron dynamics. Differential transmission decay times and their spectral dependence were used to evaluate electron-phonon scattering for polar optical (PO) and intervalley phonons. The obtained average electron-PO phonon scattering time is 4.5 ± 0.4 fs, while the electron scattering to and from the side valley is 80 ± 5 fs. The energy between the absolute and second lowest conduction band minima is estimated to be 2.6 ± 0.1 eV.

中文翻译：

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通过超快透射光谱研究β-Ga2O3 中的电子声子散射

在透射几何中的飞秒泵浦探测实验是在掺杂 Sn 的n型β -Ga ₂ O _{3 上进行的}。当泵浦和探测波长低于带隙时，差分传输信号由自由电子动力学决定。差分传输衰减时间及其光谱依赖性用于评估极光 (PO) 和间隔声子的电子-声子散射。获得的平均电子-PO 声子散射时间为 4.5 ± 0.4 fs，而从侧谷散射的电子为 80 ± 5 fs。绝对导带最小值和第二低导带最小值之间的能量估计为 2.6 ± 0.1 eV。