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.

PCE11 (PffBT4T-2OD) synthesis with 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 as starting materials engaging Stille Coupling reaction.

General Information

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Full name	Poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3’’’-di(2-octyldodecyl)-2,2’;5’,2’’;5’’,2’’’-quaterthiophen-5,5’’’-diyl)]
Synonyms	PffBT4T-2OD
Chemical formula	(C62H88F2N2S5)n
CAS number	1644164-62-4
HOMO / LUMO	HOMO = -5.34 eV, LUMO = -3.69 eV [1]
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

Chemical Structure

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Chemical structure and product image of PCE11 (PFFBT4T-2OD)

Device Structure(s)

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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.