PCDTBT
PCDTBT high performance organic photovoltaics and air stable OFETs
 |
Poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)]. Commonly known as PCDTBT. In stock now for immediate dispatch from just £199. |
PCDTBT is one of the next generation donor materials being developed for organic photovoltaics to produce better efficiencies and lifetimes. The key properties of PCDTBT result from the lower HOMO and LUMO levels which lead to advantages over standard organic photovoltaic materials of increased open circuit voltage, longer wavelength absorption and improved stability under ambient conditions.
New batches available
Ossila is pleased to announce that it now stocks a variety of PCDTBT with different molecular weights and polydispersities.
These new batches have been separated and purified by Sohxlet extraction to provide a more versatile range of uses. We now have molecular weights ranging from 34,800 to 82,200 and polydispersities between 1.76 and 3. In general PCDTBT has lower solubility than materials such as P3HT and so the lower molecular weight fractions are recommended for use in scale-up activities while the higher molecular weight fractions can provide higher fill factors but at the expense of ease of processing.
| Product Code | Soxhlet Fraction | Mw | Mn | PDI |
|---|---|---|---|---|
| M132 | Crude | 82,200 | 27,300 | 3.01 |
| M133 | Toluene | 35,400 | 14,500 | 2.44 |
| M134 | Chloroform | 34,800 | 15,000 | 2.32 |
| M135 | Chlorobenzene | 38,800 | 21,500 | 1.80 |
| M136 | Dichlorobenzene | 61,600 | 34,900 | 1.76 |
The different molecular weights correspond to different fractions extracted by consecutive solvents (see table above) and allow users to select the best material for their own research. The lower lying HOMO level of PCDTBT makes it much more stable under ambient conditions and therefore an ideal candidate to use with large area deposition methods such as ink-jet printing, spray coating and blade coating. However, for these deposition techniques, uniform, aggregate free coatings are essential and so lower molecular weights are often desirable. Meanwhile, the highest reported efficiencies for PCDTBT have generally been from higher molecular weight fractions.
By stocking a range of materials Ossila is now able to cater for a much wider range of research activities.
Back to top
Availability
The below materials are in stock for immediate dispatch to research institutions in Europe (and selected other countries outside of North America). They can be bought online via Google Checkout or via a standard purchase order.
In general, PCDTBT is used at lower concentrations than P3HT (typically 4 to 7 mg/ml) and higher blend ratios (1:4 PCDTBT:PC70BM) and as such 100 mg of PCDTBT will make around 500 devices on Ossila's standard ITO substrates (20 x 15 mm) even assuming 50% material loss in filtration and solution preperation. Please note that as the higher molecular weight fractions have a lower yield we are now operating differential pricing policy. See below for more details on separation, yield and differential pricing.
| Product Code | Soxhlet Fraction | Mw | Price per 100 mg |
|---|---|---|---|
| M132 | Crude | 82,200 | £199 |
| M133 | Toluene | 35,400 | £299 |
| M134 | Chloroform | 34,800 | £349 |
| M135 | Chlorobenzene | 38,800 | £449 |
| M136 | Dichlorobenzene | 61,600 | - |
Please note that PCDTBT is currently unavailable to buyers in the USA. Any incoming orders from the USA for PCDTBT will not be processed. We are working to try and resolve this issue.
Back to top
Soxhlet details
All Ossila PCDTBT batches have been purified by soxhlet extraction with acetone, methanol and hexane to remove impurities and catalysts as well as residual monomers and end-capping. These solvents will dissolve the unwanted materials but are not solvents for the PCDTBT itself and so after this purification procedure the PCDTBT is clean but has a wide range of molecular weights. This includes a small percentage of very long chain polymers with molecular weight approaching one million which are highly insoluble. It also includes some low molecular weigh oligomers. At this point we term the PCDTBT "crude."
Separation of the different molecular weight fractions is then performed by further soxhlet extractions using successively improved solvents: toluene, chloroform, chlorobenzene and finally dichlorobenzene. The less good solvents such as toluene and chloroform dissolve the lower molecular weight fractions leaving the higher molecular weight parts behind (see GPC graphs below). As such, with successive solvents the molecular weight increases and polydispersity decreases. Finally, depending upon the reaction, there is a small amount of insoluble material remaining which is discarded.
Download the full data for the distributions here
Overall, the second stage of soxhlet extraction reduces the yield of material by around 50% and is one of the longest parts of the overall production of PCDTBT. As such, the purified PCDTBT has a significantly higher cost associated with it. Meanwhile, the molecular weight distribution of the crude material means that exponentially less material is produced for the higher soxlet fractions (chlorobenzene and dichlorobenzene) as shown in the graph below and so again these materials have additional cost.
Back to top
| Other products you may be interested in... |
 |
 |
 |
|
Printable HTML MSDS |
Usage Datasheet |
|
For high performance organic photovoltaics with efficiencies approaching 5%
poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT)
 |
Ossila is pleased to announce that it now has PCDTBT in stock for delivery to research institutions in Europe and other territories outside of North America. In a standard organic photovoltaic configuration we have achieved an efficiency of 4.9% (see below for fabrication details) and using a metal oxide interfaces have achieved 5.1% (publication pending, please contact us for details).
 |
| Batch# | 001 |
| Mn | 16,700 |
| Mw | 33,600 |
| PDI | 2.01 |
| HOMO/LUMO | -5.3 eV / -3.5 eV |
| Bandgap | ~1.8eV |
| CAS no | 958261-50-2 |
Solution Details
Ossila’s reference devices were made by dissolving PCDTBT (batch 001) at 4 mg/ml in anhydrous chloroform using a stir-bar and hotplate at 80ºC before filtering through 5 µm and then 0.45 µm PTFE filters. This was then mixed with Ossila’s dry 95% C70 PCBM powder in a 1:4 blend ratio to produce an overall concentration of 20 mg/ml.
The blend solution was heated with a stir-bar on a hotplate at 80ºC for 60 hours
before cooling to approximately room temperature over 5 minutes and filtering again with a 0.45 um PTFE filter immediately prior to spinning at 3000 RPM to give a film of ~ 65 nm.
Note that the high molecular weight fraction in this batch enable highest performance but this means some insoluble components will be visible as aggregates in solution before filtering.
Device Structure
Glass/ITO/PEDOT:PSS/PCDTBT:PC70BM/Ca/Al
Ossila’s pre-patterned ITO substrates with 100 nm (20 Ohm/square) ITO were prepared by removing the protective photoresist by ultransonication in a hot NaOH solution. After rinsing in DI water they were blown dry before spin-coating the hole transport layer (no further cleaning or surface treatment required).
PEDOT:PSS (AI4083 from Ossila) was diluted 2:1 with DI water and filtered through a 0.45 um PVDF filter before spin coating at 5000 RPM in air to produce
a layer ~20 nm thick). The coated substrates were then stored on a hotplate at 150 C before transfer into a glovebox and a further bake of 150 C for 10 mins to remove any residual moisture.
The active ink was spin cast and the cathode strip wiped clean before transfer to an evaporator where 5 nm of Ca followed by 100 nm of Al were deposited at < 10-6 mbar. The substrates were then annealed at 80 C for 30 mins on a hotplate in the glovebox before protecting with the Ossila encapsulation system.
Measurement was performed under ambient conditions using a Newport 92251A
AM1.5 100 mW/cm2 solar simulator and NREL certified silicon reference cell.
Advantages
PCDTBT is one of the next generation donor materials being developed for organic photovoltaics to produce better efficiencies and lifetimes. The key properties of PCDTBT result from the lower HOMO and LUMO levels which lead to the advantages over standard organic photovoltaic materials (such as P3HT) of:
| Increased open circuit voltage |
| Longer wavelength absorption |
| Lower concentration and material usage |
| Improved stability under ambient conditions |
Ordering
Ossila’s PCDTBT is in stock now for immediate delivery to European research institutes and can be dispatched upon receipt of a purchase order from your institution.
For current pricing please visit Ossila.com or email Sales@Ossila.com.
Typically sold in 100 mg quantities (for larger quantities please contact us). When used in solutions at the optimum concentration of 4 mg/ml this allows up to 25 ml of solution to be created from a single lot. Coating one of Ossila’s standard sized ITO substrates requires ~25 µl of solution. Therefore a 100 mg lot of PCDTBT will make around 500 devices assuming only 50% utilisation during filtering and solution preparation.
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.
Back to top
OLED/OPV components
PCDTBT, P3HT, PCBM and PEDOT:PSS.
OFET components
OLED/OPV overview
OFET overview
