We examine the dynamics of polaron recombination in conjugated polymer syst
ems using mixed quantum classical molecular dynamics. The model treats the
particle-hole pair as a fully correlated two-particle quantum mechanical wa
ve function interacting with a one-dimensional classical vibrational lattic
e. This description allows a natural evolution of the particle-hole wave fu
nction from the polaron limit to the exciton limit, and we have performed r
eal-time simulations of the coupled nuclear and electronic dynamics associa
ted with the scattering of polarons into exciton states. We use these simul
ations to calculate cross sections for exciton formation as a function of s
pin state, and explore the variation of these cross sections with respect t
o changes in the magnitude of the particle-hole Coulomb interaction and the
effective masses of the quasiparticles. Our results indicate that for an o
ptimal choice of parameters the electroluminescence quantum yield may be as
high as 59%, substantially greater than the 25% predicted by simple spin s
tatistics. We interpret these results in a diabatic framework, and suggest
strategies for the design of organic systems for use in electroluminescent
devices.