Abstract
Carrier diffusion and electron-hole recombination are shown to be considerably slowed down in semimagnetic semiconductors due to the efficient trapping of electrons on manganese sites. The theoretical interpretation is based on population dynamics, charge continuity equations, and Poisson’s law. A simple analytical solution of this complicated system of equations is in very good agreement with the numerical one for a large range of durations of the write pulses (from 100 ps to 1 μs). Both calculations predict a reduction of electron mobility by a factor of 6000. These theoretical predictions are confirmed by the results of an experimental study performed by using the simple grating technique: We observe the temporal evolution of the diffracted signal when a continuous read beam is used to read gratings of different wavelengths encoded in the material by interfering write laser pulses. An effective ambipolar mobility of is measured, which provides a value of for the intrinsic mobility in This low ambipolar mobility could make this efficient material potentially interesting for parallel optical processing in the microsecond range.
- Received 23 February 1998
DOI:https://doi.org/10.1103/PhysRevB.58.7753
©1998 American Physical Society