Combined impact of entropy and carrier delocalization on charge transfer exciton dissociation at the donor-acceptor interface

Several models of the charge transfer exciton (CTE) have been proposed to explain its dissociation at the donor-acceptor (DA) interface. However, the underlying physics is still under debate. Here, we derive temperature ($T$)-dependent tight-binding model for an electron-hole pair at the DA interface. The main finding is the existence of the localization-delocalization transition at a critical $T$, which can explain the CTE dissociation. The present study highlights the combined effect of entropy (finite-$T$) and carrier delocalization in the CTE dissociation.