Abstract
Dynamics of photo-excited carrier relaxation
processes in cadmium selenide nanocrystal thin films
prepared by chemical bath deposition method have been
studied by nondegenerate femtosecond transient
pump-probe spectroscopy. The carriers were generated
by exciting at 400 nm laser light and
monitored by several other wavelengths. The induced
absorption followed by a fast bleach recovery observed
near and above the bandgap indicates that the
photo-excited carriers (electrons) are first trapped
by the available traps and then the trapped electrons
absorb the probe light to show a delayed absorption
process. The transient decay kinetics was found to be
multiexponential in nature. The short time constant,