Poly{4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b :4,5-b ']dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4- b ]thiophene-4,6-diyl}

PTB7 for high-performance organic photovoltaics.
Poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]], more commonly known as PTB7.
PTB7 gives some of the highest reported efficiencies for polymer:fullerene solar cells due to its extended absorption into the near infra-red and lower HOMO level. Together with our complete package of processing information, PTB7 becomes a quick and easy way to improve device efficiencies. This represents a cost-effective method to increase performance and impact of devices and data for a wide range of OPV related research.
At typical concentrations for spin-coated devices of 10 mg/ml, a standard batch of 100 mg will produce 10 ml of ink - enough to coat 200 of Ossila's standard sized substrates even assuming 50% ink loss during preparation and filtration. At concentrations of 1 mg/ml (more typical for ink-jet printing and spray coating) up to 100 ml of ink can be produced.
In a standardised reference architecture (using a PEDOT:PSS hole interface and Ca/Al electron interface) we have shown this batch to give a PCE of 6.8% (see data sheet below) and up to 7.4% using PFN. By using new interface materials and architectures PTB7 has been shown to reach efficiencies of 9.2% PCE in the literature.
The high solubility in a wide range of solvents makes ink preparation and filtration simple, and PTB7 is one of the easiest materials we have ever worked with (simply shake it to dissolve). This also makes it an excellent candidate for a variety of coating techniques including ink-jet printing, spray coating and blade coating.

PTB7 gives some of the highest reported efficiencies for polymer:fullerene solar cells due to its extended absorption into the near infra-red and lower HOMO level. Together with our complete package of processing information, PTB7 becomes a quick and easy way to improve device efficiencies. This represents a cost-effective method to increase performance and impact of devices and data for a wide range of OPV related research.

It is majorly used as an active layer that enhances the overall performance by increasing the light absorption and improving the electron mobility of polymeric solar cells (PSCs).

PTB7 is a semiconducting polymer used in organic photovoltaics with an energy efficiency of 9.15%. It can act as an electron donor with narrow optical band gaps and excellent π-π conjugation while forming a nanocomposite with fullerenes.