Gast ::
| Hauptseite > Publikationsdatenbank > The role of exciton lifetime for charge generation in organic solar cells at negligible energy-level offsets |
| Hauptseite > Publikationsdatenbank > The role of exciton lifetime for charge generation in organic solar cells at negligible energy-level offsets |
| Journal Article | FZJ-2021-00671 |
; ; ; ; ; ; ; ; ;
2020
Nature Publishing Group
London
This record in other databases: 
Please use a persistent id in citations: http://hdl.handle.net/2128/27279 doi:10.1038/s41560-020-00684-7
Abstract: Organic solar cells utilize an energy-level offset to generate free charge carriers. Although a very small energy-level offset increases the open-circuit voltage, it remains unclear how exactly charge generation is affected. Here we investigate organic solar cell blends with highest occupied molecular orbital energy-level offsets (∆EHOMO) between the donor and acceptor that range from 0 to 300 meV. We demonstrate that exciton quenching at a negligible ∆EHOMO takes place on timescales that approach the exciton lifetime of the pristine materials, which drastically limits the external quantum efficiency. We quantitatively describe this finding via the Boltzmann stationary-state equilibrium between charge-transfer states and excitons and further reveal a long exciton lifetime to be decisive in maintaining an efficient charge generation at a negligible ∆EHOMO. Moreover, the Boltzmann equilibrium quantitatively describes the major reduction in non-radiative voltage losses at a very small ∆EHOMO. Ultimately, highly luminescent near-infrared emitters with very long exciton lifetimes are suggested to enable highly efficient organic solar cells.
; 
; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Essential Science Indicators ; IF >= 50 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection
|
The record appears in these collections: |
PDF PDF
Fulltext by OpenAccess repository