TY - JOUR
T1 - Towards understanding the doping mechanism of organic semiconductors by Lewis acids
AU - Yurash, Brett
AU - Cao, David Xi
AU - Brus, Viktor V.
AU - Leifert, Dirk
AU - Wang, Ming
AU - Dixon, Alana
AU - Seifrid, Martin
AU - Mansour, Ahmed E.
AU - Lungwitz, Dominique
AU - Liu, Tuo
AU - Santiago, Peter J.
AU - Graham, Kenneth R.
AU - Koch, Norbert
AU - Bazan, Guillermo C.
AU - Nguyen, Thuc Quyen
N1 - Publisher Copyright:
© 2019, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Precise doping of organic semiconductors allows control over the conductivity of these materials, an essential parameter in electronic applications. Although Lewis acids have recently shown promise as dopants for solution-processed polymers, their doping mechanism is not yet fully understood. In this study, we found that B(C6F5)3 is a superior dopant to the other Lewis acids investigated (BF3, BBr3 and AlCl3). Experiments indicate that Lewis acid–base adduct formation with polymers inhibits the doping process. Electron–nuclear double-resonance and nuclear magnetic resonance experiments, together with density functional theory, show that p-type doping occurs by generation of a water–Lewis acid complex with substantial Brønsted acidity, followed by protonation of the polymer backbone and electron transfer from a neutral chain segment to a positively charged, protonated one. This study provides insight into a potential path for protonic acid doping and shows how trace levels of water can transform Lewis acids into powerful Brønsted acids.
AB - Precise doping of organic semiconductors allows control over the conductivity of these materials, an essential parameter in electronic applications. Although Lewis acids have recently shown promise as dopants for solution-processed polymers, their doping mechanism is not yet fully understood. In this study, we found that B(C6F5)3 is a superior dopant to the other Lewis acids investigated (BF3, BBr3 and AlCl3). Experiments indicate that Lewis acid–base adduct formation with polymers inhibits the doping process. Electron–nuclear double-resonance and nuclear magnetic resonance experiments, together with density functional theory, show that p-type doping occurs by generation of a water–Lewis acid complex with substantial Brønsted acidity, followed by protonation of the polymer backbone and electron transfer from a neutral chain segment to a positively charged, protonated one. This study provides insight into a potential path for protonic acid doping and shows how trace levels of water can transform Lewis acids into powerful Brønsted acids.
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U2 - 10.1038/s41563-019-0479-0
DO - 10.1038/s41563-019-0479-0
M3 - Article
C2 - 31527809
AN - SCOPUS:85073832991
SN - 1476-1122
VL - 18
SP - 1327
EP - 1334
JO - Nature Materials
JF - Nature Materials
IS - 12
ER -