Details

Autor(en) / Beteiligte

• Lin, Yuanbao
• Magomedov, Artiom
• Firdaus, Yuliar
• Kaltsas, Dimitris
• El‐Labban, Abdulrahman
• Faber, Hendrik
• Naphade, Dipti R.
• Yengel, Emre
• Zheng, Xiaopeng
• Yarali, Emre
• Chaturvedi, Neha
• Loganathan, Kalaivanan
• Gkeka, Despoina
• AlShammari, Sanaa H.
• Bakr, Osman M.
• Laquai, Frédéric
• Tsetseris, Leonidas
• Getautis, Vytautas
• Anthopoulos, Thomas D.

Titel

18.4 % Organic Solar Cells Using a High Ionization Energy Self‐Assembled Monolayer as Hole‐Extraction Interlayer

Ist Teil von

• ChemSusChem, 2021-09, Vol.14 (17), p.3569-3578

Ort / Verlag

Germany: Wiley Subscription Services, Inc

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Self‐assembled monolayers (SAMs) based on Br‐2PACz ([2‐(3,6‐dibromo‐9H‐carbazol‐9‐yl)ethyl]phosphonic acid) 2PACz ([2‐(9H‐Carbazol‐9‐yl)ethyl]phosphonic acid) and MeO‐2PACz ([2‐(3,6‐dimethoxy‐9H‐carbazol‐9‐yl)ethyl]phosphonic acid) molecules were investigated as hole‐extracting interlayers in organic photovoltaics (OPVs). The highest occupied molecular orbital (HOMO) energies of these SAMs were measured at −6.01 and −5.30 eV for Br‐2PACz and MeO‐2PACz, respectively, and found to induce significant changes in the work function (WF) of indium‐tin‐oxide (ITO) electrodes upon chemical functionalization. OPV cells based on PM6 (poly[(2,6‐(4,8‐bis(5‐(2‐ethylhexyl‐3‐fluoro)thiophen‐2‐yl)‐benzo[1,2‐b:4,5‐b’]dithiophene))‐alt‐(5,5‐(1’,3’‐di‐2‐thienyl‐5’,7’‐bis(2‐ethylhexyl)benzo[1’,2’‐c:4’,5’‐c’]dithiophene‐4,8‐dione)]) : BTP‐eC9 : PC71BM ([6,6]‐phenyl‐C71‐butyric acid methyl ester) using ITO/Br‐2PACz anodes exhibited a maximum power conversion efficiency (PCE) of 18.4 %, outperforming devices with ITO/MeO‐2PACz (14.5 %) and ITO/poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT : PSS) (17.5 %). The higher PCE was found to originate from the much higher WF of ITO/Br‐2PACz (−5.81 eV) compared to ITO/MeO‐2PACz (4.58 eV) and ITO/PEDOT : PSS (4.9 eV), resulting in lower interface resistance, improved hole transport/extraction, lower trap‐assisted recombination, and longer carrier lifetimes. Importantly, the ITO/Br‐2PACz electrode was chemically stable, and after removal of the SAM it could be recycled and reused to construct fresh OPVs with equally impressive performance. Super SAM: Two self‐assembled monolayers (SAMs; Br‐2PACz and MeO‐2PACz) are investigated as hole‐extracting interlayer in organic photovoltaics and compared against the widely used PEDOT : PSS. Cells based on the ternary bulk‐heterojunction blend PM6 : BTP‐eC9 : PC71BM and ITO/Br‐2PACz as the anode exhibit the highest power conversion efficiency of 18.4 %, outperforming devices with ITO/MeO‐2PACz (14.5 %) and even ITO/PEDOT : PSS (17.5 %).