New Generation Hole Transporting Materials for Perovskite Solar Cells: Amide-Based Small-Molecules with Nonconjugated Backbones

Petrus, Michiel L.; Schutt, Kelly; Sirtl, Maximilian T.; Hutter, Eline M.; Closs, Anna C.; Ball, James M.; Bijleveld, Johan C.; Petrozza, Annamaria; Bein, Thomas; Dingemans, Theo J.; Savenije, Tom J.; Snaith, Henry and Docampo, Pablo (2018): New Generation Hole Transporting Materials for Perovskite Solar Cells: Amide-Based Small-Molecules with Nonconjugated Backbones. In: Advanced Energy Materials, Vol. 8, No. 32, 1801605

Abstract

State-of-the-art perovskite-based solar cells employ expensive, organic hole transporting materials (HTMs) such as Spiro-OMeTAD that, in turn, limits the commercialization of this promising technology. Herein an HTM (EDOT-Amide-TPA) is reported in which a functional amide-based backbone is introduced, which allows this material to be synthesized in a simple condensation reaction with an estimated cost of <$5 g(-1). When employed in perovskite solar cells, EDOT-Amide-TPA demonstrates stabilized power conversion efficiencies up to 20.0% and reproducibly outperforms Spiro-OMeTAD in direct comparisons. Time resolved microwave conductivity measurements indicate that the observed improvement originates from a faster hole injection rate from the perovskite to EDOT-Amide-TPA. Additionally, the devices exhibit an improved lifetime, which is assigned to the coordination of the amide bond to the Li-additive, offering a novel strategy to hamper the migration of additives. It is shown that, despite the lack of a conjugated backbone, the amide-based HTM can outperform state-of-the-art HTMs at a fraction of the cost, thereby providing a novel set of design strategies to develop new, low-cost HTMs.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy > Department of Chemistry
• Research Centers: Center for NanoScience (CENS)
• Subjects: 500 Science > 500 Science; 500 Science > 540 Chemistry
• ISSN: 1614-6832
• Language: English