Fused dithienogermolodithiophene low band gap polymers for high-performance organic solar cells without processing additives.
We report the synthesis of a novel ladder-type fused ring donor, dithienogermolodithiophene, in which two thieno[3,2-b]thiophene units are held coplanar by a bridging dialkyl germanium. Polymerization of this extended monomer with N-octylthienopyrrolodione by Stille polycondensation afforded a polymer, pDTTG-TPD, with an optical band gap of 1.75 eV combined with a high ionization potential. Bulk heterojunction solar cells based upon pDTTG-TPD:PC(71)BM blends afforded efficiencies up to 7.2% without the need for thermal annealing or processing additives.
Department of Chemistry, Centre for Plastic Electronics, Imperial College London, London, SW7 2AZ, UK.
Hongliang
H
Zhong
Zhe
Z
Li
Florent
F
Deledalle
Elisa Collado
EC
Fregoso
Munazza
M
Shahid
Zhuping
Z
Fei
Christian B
CB
Nielsen
Nir
N
Yaacobi-Gross
Stephan
S
Rossbauer
Thomas D
TD
Anthopoulos
James R
JR
Durrant
Martin
M
Heeney
D011211:Electric Power Supplies; D006576:Heterocyclic Compounds, 4 or More Rings / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D012993:Solar Energy
D006576:Heterocyclic Compounds, 4 or More Rings; D009942:Organometallic Compounds; D011108:Polymers