Self-assembled Monolayer Enables HTL-free Organic Solar Cells with 18% Efficiency and Improved Operational Stability

Yuanbao Lin, Yuliar Firdaus, Furkan Halis Isikgor, Mohamad Insan Nugraha, Emre Yengel, George T Harrison, Rawad Hallani, Abdulrahman El Labban, Hendrik Faber, Chun Ma, Xiaopeng Zheng, Anand Selvin Subbiah, Calvyn Travis Howells, Osman Bakr, Iain McCulloch, Stefaan De Wolf, Leonidas Tsetseris, Thomas D. Anthopoulos

Research output: Contribution to journalArticlepeer-review

455 Scopus citations


We report on bulk-heterojunction (BHJ) organic photovoltaics (OPVs) using the self-assembled monolayer (SAM) 2PACz as a hole-selective interlayer functionalized directly onto the indium tin oxide (ITO) anode. The 2PACz is found to change the work function of ITO while simultaneously affecting the morphology of the BHJ deposited atop. Cells with PM6:N3 BHJ and ITO-2PACz anode exhibit a power conversion efficiency (PCE) of 16.6%, which is higher than that measured for bare ITO (6.45%) and ITO/PEDOT:PSS (15.94%) based devices. The enhanced performance is attributed to lower contact-resistance, reduced bimolecular recombination losses, and improved charge transport within the BHJ. Importantly, the ITO-2PACz-based OPVs show a dramatically improved operational stability when compared with PEDOT:PSS-based cells. When the ITO-2PACz anode is combined with the ternary PM6:BTP-eC9:PC71BM BHJ, the resulting cells exhibit a maximum PCE of 18.03%, further highlighting the potential of engineered SAMs for use in hole-selective contacts in high-performance OPVs.
Original languageEnglish (US)
JournalACS Energy Letters
StatePublished - Aug 18 2020

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): OSR2018-CARF/CCF-3079
Acknowledgements: This publication is based upon work supported by the King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under Award No: OSR2018-CARF/CCF-3079. L. T. acknowledges support for the computational time granted from GRNET in the National HPC facility -ARIS - under project STEM-2.


Dive into the research topics of 'Self-assembled Monolayer Enables HTL-free Organic Solar Cells with 18% Efficiency and Improved Operational Stability'. Together they form a unique fingerprint.

Cite this