Photoinduced charge separation in the carbon nano-onion C60@C240

The double-shell fullerene C60@C240 formed by inclusion of C60 into C240 is the smallest stable carbon nano-onion. In the paper, we analyze in detail the character of excited states of C60@C240 in terms of exciton localization and charge transfer between the inner and outer shells. The unique struct...

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Detalles Bibliográficos
Autores: Voityuk, Alexander A., Solà i Puig, Miquel
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2016
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10256/12660
Acceso en línea:http://hdl.handle.net/10256/12660
Access Level:acceso abierto
Palabra clave:Transferència de càrrega
Ful·lerens
Charge transfer
Fullerenes
Dinàmica molecular
Molecular dynamics
Descripción
Sumario:The double-shell fullerene C60@C240 formed by inclusion of C60 into C240 is the smallest stable carbon nano-onion. In the paper, we analyze in detail the character of excited states of C60@C240 in terms of exciton localization and charge transfer between the inner and outer shells. The unique structure of the buckyonion leads to a large electrostatic stabilization of charge-separated (CS) states in the C60@C240. As a result, the CS states C60+@C240 lie in the same region of the electronic spectrum (2.4-2.6 eV) as strongly absorbing locally excited states, and therefore, can be effectively populated. The CS states C60 @C240+ are found to be by 0.5 eV higher in energy than the states C60+@C240 . Unlike the situation observed in donor-acceptor systems, the energy of the CS states in C60@C240 does not practically depend on the environment polarity. This leads to exceptionally small reorganization energies for electron transfer between the shells. Electronic couplings for photoinduced charge separation and charge recombination processes are calculated. The absolute rate of the formation of the CS states C60+@C240 is estimated at ~ 4 ps-1. The electronic features found in C60@C240 are likely to be shared by other carbon nano-onions