  Systematic time-resolved measurements on neutral and charged excitonic
complexes (X, XX, X+, and XX+) of 26 different single InAs/GaAs quantum dots
are reported. The ratios of the decay times are discussed in terms of the
number of transition channels determined by the excitonic fine structure and a
specific transition time for each channel. The measured ratio for the neutral
complexes is 1.7 deviating from the theoretically predicted value of 2. A ratio
of 1.5 for the positively charged exciton and biexciton decay time is predicted
and exactly matched by the measured ratio indicating identical specific
transition times for the transition channels involved.
