Investigating ultrafast carrier dynamics in perovskite solar cells with an extended π-conjugated polymeric diketopyrrolopyrrole layer for hole transportation. Issue 11 (12th February 2020)

• Record Type: Journal Article
• Authors: Kulshreshtha, Chandramouli; Clement, Arul; Pascher, Torbjörn; Sundström, Villy; Matyba, Piotr
• Is Part Of: RSC advances. Volume 10:Issue 11(2020)
• Page Start: 6618
• Page End: 6624
• Publication Date: 2020-02-12
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c9ra10009a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Diketopyrrole based hole-transport organic semiconductor was employed in perovskite solar cells and charge carrier dynamics was explained. Abstract : Here, we show a new diketopyrrole based polymeric hole-transport material (PBDTP-DTDPP, (poly[[2, 5-bis(2-hexyldecyl)-2, 3, 5, 6-tetrahydro-3, 6-dioxopyrrolo[3, 4- c ]pyrrole-1, 4-diyl]- alt -[[2, 2′-(4, 8-bis(4-ethylhexyl-1-phenyl)-benzo[1, 2- b :4, 5- b ′]dithiophene)bis-thieno[3, 2- b ]thiophen]-5, 5′-diyl]])) for application in perovskite solar cells. The material performance was tested in a solar cell with an optimized configuration, FTO/SnO2 /perovskite/PBDTP-DTDPP/Au, and the device showed a power conversion efficiency of 14.78%. The device charge carrier dynamics were investigated using transient absorption spectroscopy. The charge separation and recombination kinetics were determined in a device with PBDTP-DTDPP and the obtained results were compared to a reference device. We find that PBDTP-DTDPP enables similar charge separation time (<∼4.8 ps) to the spiro-OMeTAD but the amount of nongeminate recombination is different. Specifically, we find that the polymeric PBDTP-DTDPP hole-transport layer (HTL) slows-down the second-order recombination much less than spiro-OMeTAD. This effect is of particular importance in studying the charge transportation in optimized solar cell devices with diketopyrrole based HTL materials.