Transient-grating techniques are used to investigate the picosecond dynamics of photoexcited carriers in a range of n- and p-doped ZnSe thin-film layers grown by molecular-beam epitaxy. Two-photon absorption is employed experimentally to generate known excitation levels, comparable with those under laser action in II-VI diode structures. The analysis of the measured grating decays, incorporating photon recycling, reveals carrier lifetimes of the order of 300 ps and radiative recombination coefficients of the order of 10-8 cm3 s-1. The influence of photon-assisted plasma expansion at excitation levels above the threshold for stimulated emission is modeled and quantified. © 1996 Optical Society of America.
|Number of pages
|Journal of the Optical Society of America B: Optical Physics
|Published - May 1996