  A method of data analysis is proposed for the determination of the carrier
recombination processes in optically excited matter measured by time-resolved
photoluminescence, differentiating monomolecular, bi-molecular, tri-molecular,
and higher order molecular processes. Our method allows to determine whether
the so-called ABC model describes time evolution of optical relaxation of the
excited system. The procedure is applicable to the time evolution of any
optically excited medium. As an illustration, the method is successfully
applied to III-nitride polar and non-polar multi-quantum wells. We show that in
this case the mono- and bi-molecular processes determine the carrier
relaxation, and the tri-molecular Auger recombination contribution is
negligible.
