Jacket‐like structure of donor–acceptor chromophores‐based conducting polymers for photovoltaic cell applications

Abstract

Through the Stille coupling polymerization, a series of soluble acceptor/donor quinoxaline/thiophene alternating conducting polymers with a hole‐transporting moiety of carbazole as a side chain (PCPQT) has been designed, synthesized, and investigated. The UV–vis measurement of the charge‐transferred type PCPQTs of different molecular weights with low polydispersity exhibits a red shifting of their absorption maximum from 530 to 630 nm with increasing chain length (Mn: from 1100 to 19,200). The HOMO and LUMO energy levels of PCPQT can be determined from the cyclic voltammetry measurement to be −5.36 and −3.59 eV, respectively. Solar cells made from PCPQT/PCBM bulk heterojunction show a high open‐circuit voltage, Voc of ∼0.75 V, which is significantly higher than that of a solar cell made from conventional poly(3‐hexyl thiophene)/PCBM as the active polymer PCPQT has lower HOMO level. Further improvements are anticipated through a rational design of the new low band‐gap and the structurally two‐dimensional donor–acceptor conducting polymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1607–1616, 2010

Optical and electrochemical properties of polyfluorenes with pyridine–triphenylamine bipolar unit

“…To achieve high efficiency, balanced rates of injection and transport of both electrons and holes in polymeric materials are essential. To address this problem, electron‐withdrawing and electron‐donating groups were incorporated into a single polymer, creating bipolar (donor–acceptor) emissive polymers . Donor–acceptor (D–A)‐type conjugated molecules can serve as efficient electroluminescent materials , .…”

Synthesis and photovoltaic performances of benzo[1,2‐b:4,5‐b']dithiophene‐alt‐2,3‐diphenylquinoxaline copolymers pending functional groups in phenyl rings

“…The morphology of the polymer/PCBM blend film was investigated by an AFM on a Veeco, DI Multimode NS‐3D apparatus in a trapping mode under normal air condition at room temperature. Tributyl(5‐octyl‐ thiophen‐2‐yl)stannane (1), 3,6‐dibromobenzene‐1,2‐diamine, 4‐(oct‐yloxy)‐N‐(4‐(octyloxy)phenyl)‐N‐(4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)phenyl)benzen amine (3), 2,6‐bis(trimethyltin)‐4,8‐bis(2‐ethylhexyloxy)benzo[1,2‐b:4,5‐b′]dithiophene (M1) were synthesized by the published procedures 21–23…”

“…Quinoxaline is a typical electron‐deficient conjugated unit due to the strong electronegativity of its two nitrogen atoms and usually employed to construct conjugated polymers with D‐A backbone in the main chain 17–20. For example, Yang et al21 reported a series of soluble thiophene ‐alt‐ quinoxaline D‐A polymers pending a hole‐transporting carbazole moiety as a side chain and obtained the PSCs with a PCE of 0.40%. Lee et al presented a series of dioctyloxybenzo[1,2‐b;3,4‐b']dithiophene ‐alt‐ bis(2‐thienyl)‐2,3‐ diphenylbenzo[g]quinoxaline low bandgap copolymers.…”

Synthesis, characterization, and properties of new 3‐hexyl‐2,5‐diphenylthiophene: Phenylene vinylenes copolymers as colorimetric sensor for iodide anion

“…The donor–acceptor approach (D–A) is used to construct a narrow band gap polymer where a ‐(D–A) x ‐ repeat unit structure is realized by the interaction of HOMO (electron‐rich donors) and LUMO (electron‐deficient acceptors) . The D–A methodology has allowed the use of a large variety of donors and acceptors counterparts to construct a vast array of conducting polymers for a desirable optoelectronic applications . As a result, cyanovinylene spacers (acceptor units) and thiophene derivatives (donors) have been employed successfully in the (D–A) approach to construct electropolymerizable polymers with band gaps ranging from 1.1 to 1.6 eV .…”