The exceptional high mobility of this polymer of up to 10 cm2/Vs  via solution-processed techniques, combined with its intrinsic air stability (even during annealing) has made PDPP2T-TT-OD of significant interest for OFET and sensing purposes.
The exceptional high mobility of this polymer of up to 10 cm2/Vs  via solution-processed techniques, combined with its intrinsic air stability (even during annealing) has made PDPP2T-TT-ODof significant interest for OFET and sensing purposes.
While the highest mobilities require exceptional molecular weights of around 500 kD (and with commensurate solubility issues), high mobilities in the region of 1-3 cm2/Vs can still be achieved with good solution-processing at around 250 kD. As such, we have made a range of molecular weights available to allow for different processing techniques.
In our own tests, we have found that by using simple spin-coating onto an OTS-treated silicon substrate (using our prefabricated test chips), high mobilities comparable to the literature can be achieved (1-3 cm2/Vs). Further improvements may also be possible with more advanced strain-inducing deposition techniques.
Although shown as a promising hole-mobility polymer for OFETs, when used as the donor material in a bulk heterojunction photovoltaic (with PC70BM as the acceptor), initial efficiencies of 1.6% were achieved for DPP-DTT . The low device metrics were attributed to poor film morphology. However, a higher efficiency of 6.9% was achieved by using thicker film (220 nm) .
PDPP2T-TT-OD has also recently been used successfully as an active-layer dopant material in PTB7-based devices . An improvement in device performance was observed, with average efficiencies increasing from 7.6% to 8.3% when the dopant concentration of DPP-DTT was 1 wt%. The use of DPP-DTT as a high-mobility hole-interface layer for perovskite hybrid devices has also been investigated .
DPP-DTT synthesis: DPP-DTT was synthesised by following the procedures described in  and  (please refer to the following references):
With 2-thiophenecarbonitrile and dimethyl succinate as starting materials in t-amyl alcohol, it gave 3,6-Dithiophen-2-yl-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione. Alkylation of 3,6-Dithiophen-2-yl-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione with 2-octyldodecylbromide in dimethylformamide afforded 3,6-bis(thiophen-2-yl)-2,5-bis(2-octyldodecyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione. Further bromination gave 3,6-bis(5-bromothiophen-2-yl)-2,5-bis(2-octyldodecyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (M1).
Further reaction of M1 with 2,5-bis(trimethylstannyl)thieno[3,2-b]thiophene (M2) under Stille coupling conditions gave the target polymer DPP-DTT, which was further purified via Soxhlet extraction with methanol, hexane and then chloroform.
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