Donor polymers

However, not all excitons have sufficiently long lifetimes to reach the interface before recombining. To circumvent this problem and increase device efficiency, heterostmcture devices have been fabricated. In these devices, donors and acceptors are mixed together to create a network that provides many internal interfaces where charge separation can occur. Heterostmcture devices made from the donor polymer... 

The above finding led to another interesting conclusion that a minimum chain length is essential for PEG to form a stable complex with a-CD. The chain length selectivity implies that some cooperative action is involved in this complex formation as is well known in the complex formation of PEG with hydrogen-donor polymers such as poly(acrylic acid). 

Electronic Cooperativity in New tt-Donor Polymers Prepared by Modification Reactions of Poly(vinylbenzyl chloride)... 

In accord with the work of Rau [193], the EQEpv and EL data collected over a given range of temperatures and PV illumination intensities for PCBM blends with MDMO-PPV, P3HT, and APF03 donor polymers were then used, for each blend. 

Similarly to monomeric donors, side-chain donor polymers can afford formation of partially stacking donor moieties, which is necessary for high conductivity, if they achieve a smectic phase. A thiophene derivative con-... 

This mixture was prepared from 10% solutions (by weight) of donor polymer and acceptor polymer... 

Donor polymers (I) = poly(phenyliminodiethano isophthalate), (II) = poly(p-anisylimino-diethanolisophthalate), (III) = poly(p-anisyliminodiethanolbisphenol A carbonate)... 

Here are only few coordination complexes which are characterized insufficiently. Complexes of acceptor polymers from nitrophthalic adds with donor polymers from arylaminodiethanols28,29 can serve as an example. 

Pugh C, Rodriguez-Parada JM, Percec V. (1986) The influence of molecular weight of the donor polymer on the soUd-state behavior of interchain EDA complexes. J. Polym. Sci. Part A Polym. Chem. 24 747-758. 

Fig. 14 Experimentally, a linear relationship between the HOMO level of the conjugated polymer (corresponds to onset of oxidation with respect to the Ag/AgCl reference electrode) and the measured open circuit voltage ( oc) has been determined for a large number of donor polymers. (Reproduced from [102] with permission, 2006, Wiley-VCH)...

In conclusion, not only the observed larger scale of phase separation but also the difference in the material s phase percolation and thus charge transport properties influence the photovoltaic performance. As such, it becomes evident that the charge carrier mobility measured in these devices must be a function of the blend morphology [139-143]. Furthermore, the electron and hole carrier mobilities depend strongly on the polymer-fullerene blending ratio. Interestingly, the hole mobility of the donor polymer is increased considerably in blends with fullerenes (see Fig. 27) [142,144-147]. 

Synthesis via the sulfinyl route led to a reduced number of defects on the MDMO-PPV donor polymer and showed some improved performances in MDMO-PPV PCBM bulk heterojunctions [ 167,168]. The lower defect density resulted in a more regioregular (head-to-taU) order within the MDMO-PPV, leading to charge carrier mobihty improvements and ultimately to an improved efficiency of 2.65% for MDMO-PPV PCBM based bulk heterojimc-tions [ 169]. This was accompanied by a fill factor of 71% [169], which to date has not been exceeded by any other polymer solar cell device. 

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