2026-06-03T08:55:59Zhttps://riuma.uma.es/rest/oai/request

oai:riuma.uma.es:10630/246822026-02-03T12:07:18Zcom_10630_2254col_10630_37959

Triplet-charge annihilation in a small molecule donor: acceptor blend as a major loss mechanism in organic photovoltaics Marín-Beloqui, José Manuel Casado-Cordón, Juan Espectroscopía Células solares Células fotovoltaicas Resumen comunicación presentada Organic photovoltaics (OPV) are close to reaching a landmark 20% device efficiency.[1] One of the proposed reasons that OPVs have yet to attain this milestone is their propensity toward triplet formation. In this talk,[2] the small molecule donor, DRCN5T, is studied using a variety of spectroscopy techniques, and blended with both fullerene and non-fullerene acceptors. Specifically, picosecond and microsecond transient absorption and Raman spectroscopies are focused on. Despite DRCN5T's ability to achieve OPV efficiencies of over 10%,[3] it generates an unusually high population of triplets. These triplets are primarily formed in amorphous regions via back recombination from a charge transfer state. As such, triplets have a dual role in DRCN5T device efficiency suppression: they both hinder free charge carrier formation and annihilate those free charges that do form. Using microsecond transient absorption spectroscopy under oxygen conditions, this triplet-charge annihilation (TCA) is directly observed as a general phenomenon in a variety of DRCN5T: fullerene and non-fullerene blends. Since TCA is usually inferred rather than directly observed, it is demonstrated that this technique is a reliable method to establish the presence of TCA. 2022-07-15T06:12:08Z 2022-07-15T06:12:08Z 2022-07-14 2022-06-23 conference output https://hdl.handle.net/10630/24682 eng XXX Bienal de la Real Sociedad Española de Química Granada 26 Junio a 1 Julio de 2022 http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional