Optimization of narrow band-gap propylenedioxythiophene:cyanovinylene copolymers for optoelectronic applications

被引:50
作者
Galand, Emilie M.
Kim, Young-Gi
Mwaura, Jeremiah K.
Jones, Adolphus G.
McCarley, Tracy D.
Shrotriya, Vishal
Yang, Yang
Reynolds, John R. [1 ]
机构
[1] Univ Florida, Ctr Macromol Sci & Engn, Dept Chem, George & Josephine Butler Polymer Res Lab, Gainesville, FL 32611 USA
[2] Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA
[3] Univ Calif Los Angeles, Dept Mat Sci & Engn, Los Angeles, CA 90095 USA
关键词
D O I
10.1021/ma061935o
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
Four analogues of the narrow band gap poly(3,4-propylenedioxythiophenedialkyl)cyano-p-phenylenevinylene (PProDOT-R-2:CNPPV) polymer family have been designed with the goal of improving the film forming ability and utility of this family of polymers when applied in redox switchable and optoelectronic devices. These polymers were synthesized via Knoevenagel condensation with yields ranging from 40 to 80%. Number-average molecular weights between 9000 and 24 000 g mol(-1) were estimated using size exclusion chromatography, and the polymer repeat unit structures and end groups were confirmed by MALDI mass spectrometry. Linear and branched alkoxy substituents were introduced along the polymer backbone to yield materials highly soluble in chloroform, THF, and toluene, and homogeneous films were prepared by spin-coating or spray-casting from organic solutions. The identity of the substituents has a significant effect on the optical properties of the polymer solutions. A blue-shift in the absorption was observed by replacing linear alkoxy substituents with branched substituents suggesting poorer packing. The HOMO and LUMO energy levels were studied by thin film electrochemistry, and optical band gaps of 1.70-1.75 eV have been determined spectroelectrochemically from the onset of the pi to pi* transition, importantly near the wavelength of maximum solar photon flux. These narrow band gap polymers have shown significant photovoltaic performance as electron donors when combined with the electron acceptor [6, 6]-phenyl C-61-butyric acid methyl ester (PCBM) in bulk heterojunction photovoltaic devices. AM1.5 efficiencies up to similar to 0.4% were attained with short circuit current densities > 1.0 mA cm(-2), an open circuit voltage of similar to 0.7 V, and a fill factor of similar to 40%. The identity of the substituents did not have a significant influence on the solubility of the polymers (the linear and branched polymers exhibit a solubility of about 15 mg mL(-1) in chloroform) and on the films homogeneity. The solubility and film properties of the polymers along with their electrochromic behavior, switching from a neutral blue/purple state to highly transmissive gray in the oxidized and reduced states, are potentially useful in large area electrochromic displays. Polymer light-emitting diodes have been prepared with one of the polymers, exhibiting a bright red emission with lambda(max) = 704 nm.
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收藏
页码:9132 / 9142
页数:11
相关论文
共 59 条
[31]   Electrochromic organic and polymeric materials for display applications [J].
Mortimer, RJ ;
Dyer, AL ;
Reynolds, JR .
DISPLAYS, 2006, 27 (01) :2-18
[32]   Conjugated polymer photovoltaic devices and materials [J].
Mozer, Attila J. ;
Sariciftci, Niyazi Serdar .
COMPTES RENDUS CHIMIE, 2006, 9 (5-6) :568-577
[33]   MEH-PPV: Improved synthetic procedure and molecular weight control [J].
Neef, CJ ;
Ferraris, JP .
MACROMOLECULES, 2000, 33 (07) :2311-2314
[34]  
PADINGER F, 2001, APPL PHYS LETT, V78, P841
[35]   Conversion constants for redox potentials measured versus different reference electrodes in acetonitrile solutions at 25°C [J].
Pavlishchuk, VV ;
Addison, AW .
INORGANICA CHIMICA ACTA, 2000, 298 (01) :97-102
[36]   Spray coatable electrochromic dioxythiophene polymers with high coloration efficiencies [J].
Reeves, BD ;
Grenier, CRG ;
Argun, AA ;
Cirpan, A ;
McCarley, TD ;
Reynolds, JR .
MACROMOLECULES, 2004, 37 (20) :7559-7569
[37]   High-efficiency photovoltaic devices based on annealed poly(3-hexylthiophene) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61 blends -: art. no. 083506 [J].
Reyes-Reyes, M ;
Kim, K ;
Carroll, DL .
APPLIED PHYSICS LETTERS, 2005, 87 (08)
[38]   Identification and quantification of polymerization defects in 13C-labeled sulfinyl and Gilch OC1CO10-PPV by NMR spectroscopy [J].
Roex, H ;
Adriaensens, P ;
Vanderzande, D ;
Gelan, J .
MACROMOLECULES, 2003, 36 (15) :5613-5622
[39]   Investigation of the effect of donor-acceptor substitution on band gap, band width, and conductivity [J].
Salzner, U .
SYNTHETIC METALS, 2001, 119 (1-3) :215-216
[40]   Mass discrimination in the analysis of polydisperse polymers by MALDI time-of-flight mass spectrometry .1. Sample preparation and desorption/ionization issues [J].
Schriemer, DC ;
Li, L .
ANALYTICAL CHEMISTRY, 1997, 69 (20) :4169-4175