Journal article

LiTFSI-Free Spiro-OMeTAD-Based Perovskite Solar Cells with Power Conversion Efficiencies Exceeding 19%

B Tan, SR Raga, ASR Chesman, SO Fürer, F Zheng, DP McMeekin, L Jiang, W Mao, X Lin, X Wen, J Lu, YB Cheng, U Bach

Advanced Energy Materials | Wiley-VCH Verlag | Published : 2019


To date, the most efficient perovskite solar cells (PSCs) employ an n–i–p device architecture that uses a 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenyl-amine)-9,9′-spirobifluorene (spiro-OMeTAD) hole-transporting material (HTM), which achieves optimum conductivity with the addition of lithium bis(trifluoromethane)sulfonimide (LiTFSI) and air exposure. However, this additive along with its oxidation process leads to poor reproducibility and is detrimental to stability. Herein, a dicationic salt spiro-OMeTAD(TFSI)2, is employed as an effective p-dopant to achieve power conversion efficiencies of 19.3% and 18.3% (apertures of 0.16 and 1.00 cm2) with excellent reproducibility in the absence of LiTFS..

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University of Melbourne Researchers


Awarded by Australian Research Council (ARC)

Awarded by ARC Centre of Excellence in Exciton Science

Awarded by Australian Research Council

Funding Acknowledgements

The authors are grateful for the financial support by the Australian Research Council (ARC) discovery project (DP160104575), the Australian Centre for Advanced Photovoltaics (ACAP), the Australian Renewable Energy Agency, and the ARC Centre of Excellence in Exciton Science (ACEx: CE170100026). The authors also acknowledge the financial support from the Commonwealth Scientific and Industrial Research Organisation (CSIRO) as a part of science leader fellowship (U.B.), and Dr. T. Gengenbach (CSIRO) for performing the UPS measurements. Monash University Centre for Electron Microscopy (MCEM) and Monash X-ray Platform (funded by Australian Research Council grant LE130100072) are highly acknowledged. This work was performed in part at the Melbourne Centre for Nanofabrication (MCN) in the Victorian Node of the Australian National Fabrication Facility (ANFF).