Efficient and stable perovskite solar cells using molybdenum tris(dithiolene)s as p-dopants for spiro-OMeTAD

Journal article

Metal halide perovskite solar cells have now reached efficiencies of over 22%. To date, the most efficient perovskite solar cells have the n-i-p device architecture and use 2,2′,7,7′-tetrakis(N,N′-di-p-methoxyphenylamine)-9,9′-spirobifluorene or poly(triarylamine) as the hole transport material (HTM), which are typically doped with lithium bis((trifluomethyl)sulfonyl)amide (Li-TFSI). Li-TFSI is hygroscopic and detrimental to the long-term performance of the solar cells, limiting its practical use. In this work, we successfully replace Li-TFSI by molybdenum tris(1-(methoxycarbonyl)-2-(trifluoromethyl)ethane-1,2-dithiolene), Mo(tfd-CO2Me)3, or molybdenum tris(1-(trifluoroacetyl)-2-(trifluoromethyl)ethane-1,2-dithiolene), Mo(tfd-COCF3)3. With these two dopants, we achieve stabilized power conversion efficiencies up to 16.7% and 15.7% with average efficiencies of 14.8% ± 1.1% and 14.4% ± 1.2%, respectively. Moreover, we observe a significant enhancement of the long-term stability of perovskite solar cells under 85 °C thermal stressing in air.

Authors: Pellaroque, A; Noel, NK; Habisreutinger, SN; Zhang, Y; Barlow, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: ACS Energy Letters
• Volume: 2
• Issue: 9
• Pages: 2044-2050
• Publication date: 2017-08-15
• Acceptance date: 2017-08-15
• DOI: 10.1021/acsenergylett.7b00614
• ISSN: 2380-8195