Hole and electron mobilities have been measured in ternary solid solut
ions containing an electron acceptor, -4-dicyanomethylidene-2-p-tolyl-
6-phenylthiopyran, and an electron donor, tri-p-tolylamine, in a polye
ster host. The results are discussed by a model based on disorder, due
to Bassler and coworkers. The key result of this study is that the pr
esence of the donor has no effect on electron transport, nor does the
presence of the acceptor have any effect on hole transport. The interp
retation of the experimental results leads to the conclusion that the
electron and hole manifolds are independent and are not influenced by
the presence of the transport states of the oppositely charged carrier
s.