Long-Range Charge Separation Enabled by Intramoiety Delocalized Excitations in Copolymer Donors in Organic Photovoltaic Blends

Abstract

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.jpclett.3c01861. Experimental methods for sample preparation; TA spectroscopy measurements and spectro-electrochemical measurements; absorption figures; global analysis results; excitation−density dependent dynamics; GIWAX characterizations; TA characterization of the PM6 solution; estimation of the penetration depth; fitting of temporal dynamics (PDF); iDEs in other copolymers ■ AUTHOR INFORMATION

Delocalisation enables efficient charge generation in organic photovoltaics, even with little to no energetic offset

“…Our nding that delocalisation enables mixed charge generation supports the hypothesis of delocalised, partially separated intermediate states forming in single domains before they reach the interface. 27,[35][36][37][38][39][40]…”

“…3,29,30 Explaining this observation is an outstanding theoretical challenge, 3 with one hypothesis being that low offsets enable the formation of hybridised states with the character of both excitons and separated charges. [31][32][33][34] Furthermore, experimental evidence suggests that delocalised and partially separated intermediate states form within NFA phases before reaching an interface, 27,[35][36][37][38][39][40] suggesting separation may not proceed through the typical pathway involving interfacial CT states. An even greater theoretical challenge is explaining the detection of free carriers in devices made of neat materials, where there is no interfacial energetic offset, including Y6.…”