Donor-to-Donor vs Donor-to-Acceptor Interfacial Charge Transfer States in the Phthalocyanine-Fullerene Organic Photovoltaic System.
Charge transfer (CT) states formed at the donor/acceptor heterointerface are key for photocurrent generation in organic photovoltaics (OPV). Our calculations show that interfacial donor-to-donor CT states in the phthalocyanine-fullerene OPV system may be more stable than donor-to-acceptor CT states and that they may rapidly recombine, thereby constituting a potentially critical and thus far overlooked loss mechanism. Our results provide new insight into processes that may compete with charge separation, and suggest that the efficiency for charge separation may be improved by destabilizing donor-to-donor CT states or decoupling them from other states.
†Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States.|‡Department of Chemistry, Kent State University, Kent, Ohio 44242, United States.
Myeong H
MH
Lee
‡Department of Chemistry, Kent State University, Kent, Ohio 44242, United States.
Barry D
BD
Dunietz
†Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States.
Eitan
E
Geva
Fermi’s golden rule; charge transfer; constrained density functional theory (C-DFT); organic photovoltaics; range separated hybrid functional