Suppression of energy disorder by incorporating a small-molecule acceptor into binary all-polymer solar cells

Abstract

Organic photovoltaic cells based on disordered materials suffer significant energy losses that limit the power conversion efficiencies (PCEs). For all-polymer solar cells (all-PSCs), the complicated blend morphology caused by the...

Trap suppression in ordered organic photovoltaic heterojunctions

“…In addition to the basic molecular structure design, device engineering also has an important impact on the overall trap state suppression of a device by improving the phase separation and molecular crystallinity in the active layer, based on adjusting the interface interactions and the dynamics of film formation of the donor/acceptor blend. 51 Many methods, such as ternary strategy, 52–61 additive introduction, 62,63 device configuration, 64,65 etc. were employed to enhance molecular order and/or reduce trap states in OSCs.…”

“…Similarly, Hou and coworkers incorporated a small-molecule acceptor, BTA3-4F, into the PDBQx-TCl:PY-IT blend film. 53 BTA3-4F has complementary absorption spectra and cascade-type energy levels with the PDBQx-TCl:PY-IT blend film. Moreover, the PDBQx-TCl:PY-IT:BTA3-4F ternary blend film acquires improved molecular order and a smaller E U of 25.1 meV, thus contributing to a lower trap density of 3.91 × 10 16 cm −3 and higher charge carrier mobilities, enabling PDBQx-TCl:PY-IT:BTA3-4F based OSCs to achieve inhibited trap-assisted recombination, bimolecular recombination and reduced Δ E nr , thus achieving an enhanced PCE of 18.6%, compared with the binary ones.…”

Dithienoquinoxalineimide‐Based Polymer Donor Enables All‐Polymer Solar Cells Over 19 % Efficiency

“…Some benzotriazole (BTA)-type acceptors gain a significant advantage as the third component in enhancing the efficiency of ternary organic solar cells owing to their highlying LUMO energy level. [14,32] Herein, F-BTA3 was selected as the third component of QQ1 : PY-IT and the molecular structure of F-BTA3 was illustrated in Figure 7. To our delight, QQ1-based ternary device can achieve a PCE as high as 19.20 % with a V oc of 0.917 V, a J sc of 26.59 mA cm À 2 , and a FF of 78.75 % when the doping ratio of F-BTA3 reaches 15 %.…”

π-Extended Nonfullerene Acceptor for Compressed Molecular Packing in Organic Solar Cells To Achieve over 20% Efficiency

“…However, although extensive chemical and physical approaches have been dedicated to enhancing the molecular order of OPVs to enhance light absorption and charge transport, − strongly increased nonradiative energy loss has also been routinely observed in the literature, , which can be attributed to the suppressed luminescence due to increased intermolecular aggregation. Regarding that, the primary obstacle to the further PCE development in OPVs lies in the striking balance between aggregation and luminescent efficiency, − and therefore it has been well considered as a grand challenge to eliminate the trade-off between J SC and V OC.…”