so that the Langevin recombination rate is then equal to From a comparison between Eqs. (S2) and (S5), and neglecting the effect of the exciton binding energy on the local hop rates, one would then expect that For energetically disordered systems, this derivation of is for various reasons an oversimplification. Firstly, from a Kinetic Monte Carlo (KMC) study by van der Holst et al. it is known that for the case of equal electron and hole densities, the r e combination rate is given by the Langevin formula, but modified by a factor , ) (> 1), due to the need to include Coulomb-correlation effects ( “bimolecular mobili ties”).In part C of this section (Fig. 12 part (a)), we show from KMC simulations how varies with the carrier concentration and with the reduced disorder parameter / ( $_{¾}$T). Secondly, we have to include in 7 a correction for describing the r e combination rate in Eq. (S2) using a hop rate that is enhanced by including the exciton binding energy. Whereas that is physically correct when the final exciton- formation step is considered, the mobility of the recombining charges at distances larger than a NN-distance due to hops before the filial recombination step is then taken to be too large. We correct for this error by including in 7 a factor (c, ) (< 1 ) that is equal to the inverse of the average rate enhancement for a system with a uniform carrier concentration: In part C of this section (Fig. 12 part (b)), we show from KMC simulations how r$_{v}$ varies with the carrier concentration and with the disorder parameter. Thirdly, we