| Work Detail |
A team from the South China University of Science and Technology has designed a small donor molecule to act as a third component in ternary organic cells. It has helped achieve a power conversion efficiency of 18.26% when fabricated with a PM6:BTP-eC9 organic solar cell.
Scientists at the Southern University of Science and Technology in Shenzhen, China, have designed and synthesized a small-molecule dimerized donor for ternary organic solar cells.
In the article “ Dimerized small molecule donor enables efficient ternary organic solar cells ,” published in the journal Giant , the researchers explain that ternary organic solar cells are the “feasible and effective strategy” to achieve high-performance organic cells, but stress the need to develop a third component to maximize efficiency.
The dimerized small molecule donor presented in this work, DSMD-ßV, was fabricated by connecting two asymmetric small molecule donors with the vinyl group. “A small asymmetric donor with a bromine-substituted terminal group, named as a compound, was obtained through a series of ingenious synthetic strategies,” the scientists explained. “The compound was then coupled with vinyl to synthesize the target product DSMD-ßV via a Stille coupling reaction, using Pd2(dba)3 as the catalyst and P(o-tol)3 as the ligand.”
The scientists consider DSMD-ßV, an oligomeric molecule, to be a suitable third component due to its absorption, which exhibited a broad absorption range from 350 to 800 nm, and the energy level match when compared to PM6 and BTP-eC9. The team added that the introduction of DSMD-ßV can also improve the phase separation of the PM6:BTP-eC9-based film morphology.
To test the dimerized small molecule donor, the scientists fabricated a solar cell composed of DSMD-ßV and a PM6:BTP-eC9 system as a binary array. After testing, they found that the PM6:DSMD-ßV:BTP-eC9 ternary organic cell device recorded a power conversion efficiency of 18.26%, compared to 17.63% for a PM6:BTP-eC9-based binary cell.
The research highlighted that the ternary device with DSMD-ßV also achieved more efficient exciton dissociation, suppressed trap-assisted recombination, promoted charge transfer, inhibited charge recombination, and improved carrier lifetime and extraction time compared with the reference binary device.
“This work indicates that the small-molecule dimeric donor is a promising third-component candidate for constructing efficient ternary organic solar cells,” the researchers concluded, “which also opens up a unique idea for the construction of efficient ternary organic solar cells.” |
