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Oxoammonium cation of 2,2,6,6-tetramethylpiperidin-1-oxyl: a very efficient dopant for hole-transporting triaryl amines in a perovskite solar cell

Published online by Cambridge University Press:  29 January 2018

H. Maruo
Department of Applied Chemistry, Waseda University, Tokyo 169-8555, Japan
S. Tanaka
Department of Applied Chemistry, Waseda University, Tokyo 169-8555, Japan
M. Takamura
Department of Applied Chemistry, Waseda University, Tokyo 169-8555, Japan
K. Oyaizu
Department of Applied Chemistry, Waseda University, Tokyo 169-8555, Japan
H. Segawa
Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan
H. Nishide*
Department of Applied Chemistry, Waseda University, Tokyo 169-8555, Japan
Address all correspondence to H. Nishide at
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Oxoammonium cation of 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) was used as an oxidizing dopant of triaryl amines to efficiently and almost quantitatively generate radical cations of the amines or a hole carrier. The doped-triaryl amines yielded an amorphous and homogeneous layer without any residual oxidant or neutral TEMPO molecule through its sublimination or warming the layer. The TEMPO cation-doped spiro-OMeTAD [tetrakis(dimethoxyphenylamine)spirobifluorene] produced a high hole mobility of 2 × 10−4 cm2/Vs. The perovskite solar cell fabricated with the TEMPO cation-doped or residual dopant-free spiro-OMeTAD as the hole-transporting layer displayed a photo-conversion efficiency of 20.1% with durability.

Research Letters
Copyright © Materials Research Society 2018 

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