  Typically, amorphous organic materials contain high density of traps. Traps
hinder charge transport and, hence, affect various working parameters of
organic electronic devices. In this paper we suggest a simple but reliable
method for the estimation of the concentration of deep traps (traps that keep
carriers for a time much longer than the typical transport time of the device).
The method is based on the measurement of the dependence of the total charge,
collected at the electrode, on the total initial charge, uniformly generated in
the transport layer under the action of a light pulse. Advantages and
limitations of the method are discussed and an experimental example of the
estimation of the density of deep traps in photoconductive organic material
poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene (MEH-PPV) is
provided.
