PffBT4T-2OD (PCE11) is a low band-gap (1.65 eV) semiconducting polymer for organic photovoltaics (OPVs), which has reached power conversion efficiencies (PCEs) approaching 11% . These efficiencies are a result of the high crystallinity of the polymer, providing excellent hole transport mobilities on the order of 10-2 cm2V-1s-1, and the ability to use a thick active layer, resulting in improved light absorption.
The size and position of the alkyl chains of PffBT4T-2OD are critical to its temperature dependant aggregation properties, enabling control over the aggregation and crystallisation of the polymer to produce an efficient donor:acceptor film morphology.
Polymer PCE11 was targeted by reacting 4,7-bis(5-bromo-4-(2-octyldodecyl)thiophen-2-yl)-5,6-difluorobenzo[c][1,2,5]-thiadiazole with 2,5-bis(trimethylstannyl)thieno[3,2-b]thiophene engaging Stille Coupling reaction.
|HOMO / LUMO||HOMO = -5.34 eV, LUMO = -3.69 eV |
|Solubility/processing solvents||Dichlorobenzene or Chlorobenzene+dichlorobenzene (1:1 v/v) at elevated temperature ca. 110 °C|
|Classification / Family||Benzothiadiazole, Fluorinated benzothiadiazole, Heterocyclic five-membered ring, Organic semiconducting materials, Low band gap polymers, Organic Photovoltaics, Polymer Solar Cells|
The structure of the high-performance (10 - 11%) devices was:
ITO / ZnO / PffBT4T-2OD:PC70BM (200 – 300 nm) / MoO3 or V2O5 (20 nm) / Al (100 nm)
PffBT4T-2OD:PC70BM solution details:
- Blend ratio: 1:1.2,
- Polymer concentration: 9 mg/ml,
- Solvent: 1:1 blend of chlorobenzene and dichlorobenzene,
- Additive: 3% diiodooctane,
- Heating: 85°C for dissolution,
It is important to note that this solution (and the substrate being deposited onto) must be heated for spin casting, with the ideal temperature being 60 – 80°C. It is reported that a solution and substrate pre-heating temperature of 110°C should be used to allow for cooling that will occur before deposition.
Literature and Reviews
- Aggregation and morphology control enables multiple cases of high-efficiency polymer solar cells, Y. Liu, et al., Nat. Comm., 5, 5293 (2014)
- High-efficiency non-fullerene organic solar cells enabled by a difluorobenzothiadiazole-based donor polymer combined with a properly matched small molecule acceptor, J. Zhao et al., Energy Environ. Sci., 8, 520-525 (2015)
|M303||5 - 10 g*||Please enquire|
*for 5 - 10 grams order quantity, the lead time is 4-6 weeks.
|Batch number||MW||MN||PDI||Stock Info|
To the best of our knowledge the technical information provided here is accurate. However, Ossila assume no liability for the accuracy of this information. The values provided here are typical at the time of manufacture and may vary over time and from batch to batch.