Understanding the High Performance of over 15% Efficiency in Single‐Junction Bulk Heterojunction Organic Solar Cells
Résumé
The highly efficient single-junction bulk-heterojunction (BHJ) PM6:Y6 system can achieve high open circuit voltages (VOC) while maintaining exceptional fill-factor (FF) and short-circuit current (JSC) values. With a low energetic offset, the blend system was found to exhibit radiative and nonradiative recombination losses that are among the lower reported values in the literature. Recombination and extraction dynamic studies revealed that the device shows moderate non-geminate recombination coupled with exceptional extraction throughout the relevant operating conditions. Several surface and bulk characterization techniques were employed to understand the phase separation, long-range ordering, as well as donor:acceptor (D:A) inter- and intramolecular interactions at an atomic-level resolution. This was achieved using photo-conductive atomic force microscopy (pc-AFM), grazing incidence wide angle x-ray scattering (GIWAXS), and solid-state 19F Magic-Angle Spinning (MAS) NMR spectroscopy. The synergy of multifaceted characterization and
device physics was used to uncover key insights, for the first time, on the structure-property relationships of this high performing BHJ blend. Detailed information about atomically resolved D:A interactions and packing revealed that the high performance of over 15% efficiency in this blend can be correlated to a beneficial morphology that allows high JSC and FF to be retained despite the low energetic offset.
Domaines
Chimie
Fichier principal
2019_Advanced Materiaals_201903868_Authors copy.pdf (1.12 Mo)
Télécharger le fichier
Origine | Fichiers produits par l'(les) auteur(s) |
---|---|
Licence |