Abstract
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.
Highlights
Scitation.org/journal/apl the spectrum of the electron relaxation times, we evaluate the intervalley energy between the conduction band minimum and lowest energy side valley
Differential transmission decay times and their spectral dependence were used to evaluate electron-phonon scattering for polar optical (PO) and intervalley phonons
The differential transmission (DT) decay is longer; in addition, it depends on the pump photon energy
Summary
They have been successfully applied to determine the electron–PO phonon scattering times and intervalley energies in various semiconductors, including GaAs and GaN.[12–15] For b-Ga2O3, DT measurements were used to study carrier trapping to defect and impurity states[16] and hole selflocalization.[17] Here one should note that by choosing proper experimental conditions, such as pump and probe wavelengths, energies and polarizations, and doping and crystallographic orientation of the sample, different ultrafast effects can be studied by essentially the same technique.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
