Spatiotemporal mapping uncouples exciton diffusion from singlet–singlet annihilation in the electron acceptor Y6

Understanding the spatial dynamics of nanoscale exciton transport beyond the temporal decay is essential for further improvements of nanostructured optoelectronic devices, such as solar cells. The diffusion coefficient (D) of the nonfullerene electron acceptor Y6 has so far only been determined indi...

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Detalles Bibliográficos
Autores: Gerfo Morganti, Giulia Lo, Bolzonello, Luca, Bernal Texca, Francisco, Martorell Pena, Jordi|||0000-0002-8762-1162, Hulst, Niek van
Tipo de recurso: artículo
Fecha de publicación:2023
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/418082
Acceso en línea:https://hdl.handle.net/2117/418082
https://dx.doi.org/10.1021/acs.jpclett.2c03585
Access Level:acceso abierto
Palabra clave:Diffusion
Excitons
Fluorescence
Quantum mechanics
Transport properties
Àrees temàtiques de la UPC::Física
Descripción
Sumario:Understanding the spatial dynamics of nanoscale exciton transport beyond the temporal decay is essential for further improvements of nanostructured optoelectronic devices, such as solar cells. The diffusion coefficient (D) of the nonfullerene electron acceptor Y6 has so far only been determined indirectly, from singlet–singlet annihilation (SSA) experiments. Here, we present the full picture of the exciton dynamics, adding the spatial domain to the temporal one, by spatiotemporally resolved photoluminescence microscopy. In this way, we directly track diffusion and we are able to decouple the real spatial broadening from its overestimation given by SSA. We measured the diffusion coefficient, D = 0.017 ± 0.003 cm2/s, which gives a Y6 film diffusion length of ¿=¿¿¿¿¿¿¿v˜35 nm. Thus, we provide an essential tool that enables a direct and free-of-artifacts determination of diffusion coefficients, which we expect to be pivotal for further studies on exciton dynamics in energy materials.