Enhanced n-Doping Efficiency of a Naphthalenediimide-Based Copolymer through Polar Side Chains for Organic Thermoelectrics
Artikel i vetenskaplig tidskrift, 2018

N-doping of conjugated polymers either requires a high dopant fraction or yields a low electrical conductivity because of their poor compatibility with molecular dopants. We explore n-doping of the polar naphthalenediimide–bithiophene copolymer p(gNDI-gT2) that carries oligoethylene glycol-based side chains and show that the polymer displays superior miscibility with the benzimidazole–dimethylbenzenamine-based n-dopant N-DMBI. The good compatibility of p(gNDI-gT2) and N-DMBI results in a relatively high doping efficiency of 13% for n-dopants, which leads to a high electrical conductivity of more than 10–1 S cm–1 for a dopant concentration of only 10 mol % when measured in an inert atmosphere. We find that the doped polymer is able to maintain its electrical conductivity for about 20 min when exposed to air and recovers rapidly when returned to a nitrogen atmosphere. Overall, solution coprocessing of p(gNDI-gT2) and N-DMBI results in a larger thermoelectric power factor of up to 0.4 μW K–2 m–1 compared to other NDI-based polymers.

electrical conductivity

oligo ethylene glycol side chains

n-type organic thermoelectrics


doping efficiency


David Kiefer

Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

Alexander Giovannitti

Imperial College London

Hengda Sun

Linköpings universitet

Till Biskup

Albert-Ludwigs-Universitaet Freiburg

Anna Hofmann

Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

Marten Koopmans

Unknown organization

Camila Cendra

Stanford University

Stefan Weber

Albert-Ludwigs-Universitaet Freiburg

L. Jan Anton Koster

Unknown organization

Eva Olsson

Chalmers, Fysik, Eva Olsson Group

Jonathan Rivnay

Northwestern University

Simone Fabiano

Linköpings universitet

Iain McCulloch

Imperial College London

King Abdullah University of Science and Technology (KAUST)

Christian Müller

Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

ACS Energy Letters

2380-8195 (ISSN) 2380-8195 (eISSN)

Vol. 3 278-285



Textil-, gummi- och polymermaterial



Chalmers materialanalyslaboratorium