Here we report on the synthesis of two novel very low band gap (VLG) donor-acceptor polymers (Eg ≤ 1 eV) and an oligomer based on the thiadiazoloquinoxaline acceptor. Both polymers demonstrate decent ambipolar mobilities, with P1 showing the best performance of ∼10(-2) cm(2) V(-1) s(-1) for p- and n-type operation. These polymers are among the lowest band gap polymers (≲0.
View Article and Find Full Text PDFNear-infrared (NIR) polymer light-emitting diodes (PLEDs) based on a fluorene-dioctyloxyphenylene wide-gap host material copolymerized with a low-gap emitter are presented. Various loadings (1, 2.5, 10, 20 mol%) of the low-gap emitter are studied, with higher loadings leading to decreased efficiencies likely due to aggregation effects.
View Article and Find Full Text PDFTrialkyl phosphites ((RO)3P) can act as co-initiators for the diaryliodonium-induced cationic polymerization of cyclohexene oxide (CHO) or THF. A radical initiation step is also required, consistent with the essential role of a radical chain reaction of the phosphite with the iodonium salt to form polymerization-starting aryltrialkoxyphosphonium salts (ArP(+)(OR)3). We used the visible photolysis of phenylazoisobutyronitrile (PAIBN) as the radical initiation step.
View Article and Find Full Text PDFCombining a strong donor, tris(dodecyloxy)phenyl)-dithieno[3,2-b:2',3'-d]pyrrole, with a strong acceptor, 4,8-dithien-2-yl-2lambda(4)delta(2)-benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole, has yielded the lowest bandgap, soluble, spray-processable polymer to date. The polymer has access to four different redox states and shows ambipolar behavior in OFETs. Multiple techniques, including transmission/absorption spectroscopy on SWCNTs and reflectance spectroscopy on gold were used to accurately estimate the optical bandgap at 0.
View Article and Find Full Text PDFAn electron donor/acceptor pi-conjugated polymer composed of a bi-EDOT and benzobis(thiadiazole) repeat unit exhibits two reductions with a band gap ranging from approximately 0.5 to 0.8 eV depending on the method of band gap determination.
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