Physics and chemistry of nanostructured materials

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Figure 9. (a) Envelopes of the measured Kerr rotation at
B=2T in the sample of Fig. 8 taken with 1011
electrons cm−2/pulse. The resonant excitation
energy decreases from 2.70eV to 2.61eV as the
temperature varies from 5.7K to 270K. Amplitude
changes have been normalized at zero delay, (b)
5Room temperature Kerr rotation at 2T at
Eex=2.60eV and 1011 electrons cm−2/pulse. (c)
Room temperature Kerr rotation at IT with
5×1011electrons cm−2/pulse. The excitation is at
Eex=2.72eV, 20 meV above the ZnSe bandgap
energy.

Tai ngay!!! Ban co the xoa dong chu nay!!!


1.3.2 Thin films and bulk semiconductors: II–VI and III–
V systems
Systematic studies on doped ZnSe epilayers show spin lifetimes of
1.6ns at 275K and equilibrium electron concentrations as low as
5×1016cm−3, suggesting that the room temperature spin precession
which we observe is a general feature of n-doped semiconductors.
In fact, these bulk samples exhibit an even weaker temperature
dependence than seen in the QW structures, with the spin lifetime
decreasing only