  The magneto-electronic field effects in organic semiconductors at high
magnetic fields are described by field-dependent mixing between singlet and
triplet states of weakly bound charge carrier pairs due to small differences in
their Land\'e g-factors that arise from the weak spin-orbit coupling in the
material. In this work, we corroborate theoretical models for the high-field
magnetoresistance of organic semiconductors, in particular of diodes made of
the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate)
(PEDOT:PSS) at low temperatures, by conducting magnetoresistance measurements
along with multi-frequency continuous-wave electrically detected magnetic
resonance experiments. The measurements were performed on identical devices
under similar conditions in order to independently assess the magnetic
field-dependent spin-mixing mechanism, the so-called {\Delta}g mechanism, which
originates from differences in the charge-carrier g-factors induced by
spin-orbit coupling.
