The ambipolar diffusion of carriers in bulk GaAs is studied by using an ultrafast pump-probe technique with a high spatial resolution. Carriers with a pointlike spatial profile are excited by a tightly focused pump laser pulse. The spatiotemporal dynamics of the carriers are monitored by a time-delayed and spatially scanned probe pulse. Ambipolar diffusion coefficients are deduced from linear fits to the expansion of the area of the profiles, and are found to decrease from about 170 cm2 s−1 at 10 K to about 20 cm2 s−1 at room temperature. Our results are consistent with those deduced from previously measured mobilities.
Permissions were not obtained for sharing the full text of this article. Full text is available at ArXiv; see link below.
The University of Kansas prohibits discrimination on the basis of race, color, ethnicity, religion, sex, national origin, age, ancestry, disability, status as a veteran, sexual orientation, marital status, parental status, gender identity, gender expression and genetic information in the University’s programs and activities. The following person has been designated to handle inquiries regarding the non-discrimination policies: Director of the Office of Institutional Opportunity and Access, IOA@ku.edu, 1246 W. Campus Road, Room 153A, Lawrence, KS, 66045, (785)864-6414, 711 TTY.