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have to correct 7 by properly including the percolative nature of the mobility of the recombining charge carriers. From the Extended Gaussian Disorder Model (EGDM), the unipolar mobility for materials with Gaussian disorder is at small electric fields given by 

<img src='content_image/948856.jpg'>

with / ( , c)EGDM the carrier concentration enhancement of the mobility with r e spect to the mobility for small concentrations, in the independent-particle Boltzmann regime: 

The percolative motion of the charge carriers gives rise to a strong dependence of the mobility on the disorder parameter σ . In contrast, the NN-approach as used in Eq. (S2) neglects the percolative motion of the recombining charge carriers. The mobility of the recombining charge carriers is then overestimated, and expected to be given by the value obtained from the Mean Medium Approximation (MMA). In part B of this section, we show that the mobility for NN hopping in a Gaussian DOS is then 

with β = 0.562 and / ( σ , C)MMA the carrier concentration enhancement of the mobility with respect to the mobility for small concentrations, in the independent-particle Boltzmann regime, given by Eq. (S18) in subsection B. Within the MMA, the disorder parameter dependence of the mobility is thus significantly smaller than within the EGDM. 

Combination of these three corrections leads to the following final expression for the recombination prefactor : 

