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Rapid Diffusion Of Electrons In Gamnas, Christopher P. Weber, Eric A. Kittlaus, Kassandra B. Mattia, Christopher J. Waight, J. Hagmann, X. Liu, M. Dobrowolska, J. K. Furdyna
Rapid Diffusion Of Electrons In Gamnas, Christopher P. Weber, Eric A. Kittlaus, Kassandra B. Mattia, Christopher J. Waight, J. Hagmann, X. Liu, M. Dobrowolska, J. K. Furdyna
Physics
We report ultrafast transient‐grating measurements, above and below the Curie temperature, of the dilute ferromagnetic semiconductor (Ga,Mn)As containing 6% Mn. At 80 K (15 K), we observe that photoexcited electrons in the conduction band have a lifetime of 8 ps (5 ps) and diffuse at about 70 cm2/s (60 cm2/s). Such rapid diffusion requires either an electronic mobility exceeding 7700 cm2/V s or a conduction‐band effective mass less than half the GaAs value. Our data suggest that neither the scattering rate nor the effective mass of the (Ga,Mn)As conduction band differs significantly from that …
Diffusion Of Degenerate Minority Carrier In A P-Type Semiconductor, Christopher P. Weber, Eric A. Kittlaus
Diffusion Of Degenerate Minority Carrier In A P-Type Semiconductor, Christopher P. Weber, Eric A. Kittlaus
Physics
We report ultrafast transient-grating experiments on heavily p-type InP at 15 K. Our measurement reveals the dynamics and diffusion of photoexcited electrons and holes as a function of their density n in the range 2 × 1016 to 6 × 1017 cm−3. After the first few picoseconds, the grating decays primarily due to ambipolar diffusion. While, at low density, we observe a regime in which the ambipolar diffusion is electron-dominated and increases rapidly with n, it appears to saturate at 34 cm2/s at high n. We present a simple calculation that reproduces the main …