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 | Published : 2019

Abstract

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