  Multiple exciton generation (MEG) is a process in which more than one exciton
is generated upon the absorption of a high energy photon, typically higher than
two times the band gap, in semiconductor nanocrystals. It can be observed
experimentally using time resolved spectroscopy such as the transient
absorption measurements. Quantification of the MEG yield is usu- ally done by
assuming that the bi-exciton signal is twice the signal from a single exciton.
Herein we show that this assumption is not always justified and may lead to
significant errors in the estimated MEG yields. We develop a methodology to
determine proper scaling factors to the signals from the transient absorption
experiments. Using the methodology we find modest MEG yields in lead
chalcogenide nanocrystals including the nanorods.
