N-type conjugated polymers

Grignard chemistry was used as an alternative to hydroboration reaction by the Chujo team in its search for new n-type conjugated polymers for utilization in polymer energy storage systems. By this route, the syntheses of 7r-conjugated poly(p-phenylene-boranes) (15)35 (Fig. 12) and poly(ethynylene-phenylene-ethynylene-borane)s were reported.36... 

C.J. Tonzola, M.M. Alam, B.A. Bean, and S.A. Jenekhe, New soluble n-type conjugated polymers for use as electron transport materials in light-emitting diodes, Macromolecules, 37 3554-3563,2004. 

Y. Zhu, M.M. Alam, and S.A. Jenekhe, Regioregular head-to-tail poly(4-alkylquinoline)s synthesis, characterization, self-organization, photophysics, and electroluminescence of new n-type conjugated polymers, Macromolecules, 36 8958-8968, 2003. 

Poly(phenylene)s expected as a new class of n-type conjugate polymers were synthesized in high yields by the Barbier procedure 27.52... 

With other substitutes group instead of alkyl side chains, the energy levels of acceptor polymer can be modified to match that of donor materials. Fluoro-substituted n-type conjugated polymers were introduced for all-polymer solar cells with the highest reported energy conversion efficiency of 6.71% at the state of art (Jung et al, 2015). 

Jung, J.W., Jo, J.W., Chueh, C.-C., Liu, F, Jo, W.H., Russell, T.P., Jen, A.K., 2015. Eluoro-substituted n-type conjugated polymers for additive-free all-polymer bulk heterojunction solar cells with high power... 

Li H, Kim FS, Ren G, Jenekhe SA (2013) High-mobility n-type conjugated polymers based on electron-deficient tetraazabenzodifluoranthene diimide for organic electronics. J Am Chem Soc 135 14920-14923... 

One of the most promising uses of C60 involves its potential application, when mixed with 7r-conjligated polymers, in polymer solar cells. Most often the so-called bulk heterojunction configuration is used, in which the active layer consists of a blend of electron-donating materials, for example, p-type conjugated polymers, and an electron-accepting material (n-type), such as (6,6)-phenyl-Cgi -butyric acid methyl ester (PCBM, Scheme 9.6).38... 

Cevher, S.C., Unlu, N.A., Ozelcaglayan, A.C., Apaydin, D.H., Udum,Y.A.,Toppare, L., Cirpan, A, 2013. Fused structures in the polymer backbone to investigate the photovoltaic and electrochromic properties of donor-acceptor-type conjugated polymers. J. Polym. Sci. Part A Polym. Chem. 51, 1933-1941. 

Regioregular PHT, a p-type conjugated polymer, blended with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), as n-type material, is an active material for photovoltaic devices (40). The deposition methods and the induced morphology strongly influence the functionality of the active material and in turn the final charge generation performances of a photoactive layer. 

In addition to positively impacting issues of dedoping of pH and thermally sensitive polymers such as polyaniline, self-doped forms enable the combination of p- and n-type conducting polymers without their spontaneous discharging by the concerted recombination of carriers and counterions. This has resulted in the formation of conjugated polymer p/n junctions, not possible with standard conjugated polymers. ... 

Figure 13 shows the irreversible conversion of a nonconjugated poly (p-phenylene pentadienylene) to a lithiun-doped conjugated derivative which has a semiconducting level of conductivity (0.1 to 1.0 S/cm) (29). Obviously, the neutral conjugated derivative of poly (p-phenylene pentadienylene) can then be reversibly generated from the n-type doped material by electrochemical undoping or by p-type compensation. A very similar synthetic method for the conversion of poly(acetylene-co-1,3-butadiene) to polyacetylene has been reported (30), Figure 14. This synthesis of polyacetylene from a nonconjugated precursor polymer containing isolated CH2 units in an otherwise conjugated chain is to be contrasted with the early approach of Marvel et al (6) in which an all-sp3 carbon chain was employed.

Y. Yang and Q. Pei, Light-emitting electrochemical cells from a blend of p- and n-type luminescent conjugated polymers, Appl. Phys. I ett., 70 1926-1928, 1997. 

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