Picosecond absorption dynamics of photoexcited WnGaP epitax:ial films
نویسنده
چکیده
The absorption recovery of a photoexcited InGaP epitaxial film 0.4 pm thick was investigated using the pump-probe laser technique and found to have a time constant of 55 ps at room temperature. Measurements done in the temperature range of 300-50 K show the decay of the photoexcited carrier distribution to be dominated by ambipolar diffusion and surface recombination. The measured absorption recovery time constant corresponds to an ambipolar diffusion coefficient D > 2.8 cm2/s and a surface recombination velocity of S> 4 X lo5 cm/s at room temperature.
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