logo news noimage

Designing molecular materials with very large exciton diffusion lengths would remove some of the intrinsic limitations of present-day organic optoelectronic devices. Yet, the nature of excitons in these materials is still not sufficiently well understood. Here we present Frenkel exciton surface hopping, an efficient method to propagate excitons through truly nano-scale materials by solving the time-dependent Schrödinger equation coupled to nuclear motion. We find a clear correlation between diffusion constant and quantum delocalization of the exciton. In materials featuring some of the highest diffusion lengths to date, e.g. the non-fullerene acceptor Y6, the exciton propagates via a transient delocalization mechanism, reminiscent to what was recently proposed for charge transport. Yet, the extent of delocalization is rather modest, even in Y6, and found to be limited by the relatively large exciton reorganization energy. On this basis we chart out a path for rationally improving exciton transport in organic optoelectronic materials.

Giannini, S.; Peng, W.-T.; Cupellini, L.; Padula, D.; Carof, A. & Blumberger, J.
Nat. Commun. 13, 2755 (2022) https://doi.org/10.1038/s41467-022-30308-5

Pin It

MOLECOLAB - Research Group at the Department of Chemistry of the University of Pisa
Via Giuseppe Moruzzi, 13 - 56124 Pisa, Italy
Admin LogIn/LogOut  |  Privacy Policy

This website uses cookies to ensure you get the best experience

Cookies sent by this website are not used for profiling visitors or obtaining users’ personal information