Poly(diketopyrrolopyrrole-terthiophene) for Ambipolar Logic and Photovoltaics
ABSTRACT A new semiconducting polymer, PDPP3T, with alternating diketopyrrolopyrrole and terthiophene units is presented. PDPP3T has a small band gap of 1.3 eV and exhibits nearly balanced hole and electron mobilities of 0.04 and 0.01 cm(2) V(-1) s(-1), respectively, in field-effect transistors (FETs). By the combination of two identical ambipolar transistors, an inverter was constructed that exhibits a gain of approximately 30. When PDPP3T was combined with PCBM or PCBM in a 1:2 weight ratio, photovoltaic cells were made that provide a photoresponse up to 900 nm and an AM1.5 power conversion efficiency of 3.8 or 4.7%, respectively. In contrast to the almost constant FET mobility, the efficiency of the photovoltaic cells was found to be strongly dependent on the molecular weight of PDPP3T and the use of diiodooctane as a processing agent.
Full-textDOI: · Available from: Martijn Wienk, Jul 28, 2015
- SourceAvailable from: Liangliang Han
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- "Cyclic voltammetry (CV) has been widely employed to investigate the electrochemical behavior of the molecules and estimate their HOMO and LUMO energy levels  . As shown in Fig. 3, only oxidation potentials were recorded for the two molecules. "
ABSTRACT: Two new acceptor–donor–acceptor (A–D–A) type small molecules DCAO3TIDT and DCNR3TIDT, with 4,4,9,9-tetrakis(4-(dodecyloxy)phenyl)-4,9-dihydro-s-indaceno-[1,2-b:5,6-b′]dithiophene (IDT) as the core group and 2-ethylhexyl cyanoacetate (CAO) and 2-(1,1-dicyanomethylene)-3-octyl rhodanine (CNR) as different end-capped blocks, have been designed and synthesized. Both of them have been employed as donor for solution-processed bulk hetero-junction (BHJ) organic solar cells (OSCs). The two compounds showed deep highest occupied molecular orbital (HOMO) energy levels (∼−5.30 eV) and strong absorption. The DCAO3TIDT and DCNR3TIDT with PC71BM as acceptor based BHJ solar cell devices showed short circuit current density (Jsc) of 6.93 mA/cm2 and 8.59 mA/cm2, power conversion efficiency (PCE) of 3.34% and 4.27%, respectively, and with almost same open-circuit voltage (∼0.93 V), under the illumination of AM 1.5 G, 100 mW/cm2. The high Jsc for DCNR3TIDT could result from its wider and red-shifted absorption than that of DCAO3TIDT, which was probably induced by the end-capped block rhodanine derivative. The results demonstrate that the end group would be taken into full account when designing new solution-processed small molecules, which is an important factor to determine their photovoltaic properties.Organic Electronics 01/2015; 17. DOI:10.1016/j.orgel.2014.12.031 · 3.83 Impact Factor
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- "Among several morphological optimization methods, manipulation of the solvent composition has been a popular strategy  . Specifically, adding a small fraction of a secondary liquid additive into the regular solvent has successfully improved the performance of many devices      . The origin of the improved device performance and the relationship between solvent additive and blend morphology are current areas of intense research. "
ABSTRACT: Eliminating processing with halogenated solvents is desirable to achieve sustainable large-scale fabrication of organic solar cells. This work demonstrates a device processing approach completely free of halogenated solvents to yield high-performance (power conversion efficiency, ηP > 6%) polymer:fullerene bulk-heterojunction solar cells comprising a conjugated polymer PIDT-phanQ and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM). Introducing 2% 1-methylnaphthalene (Me-naph) as a processing additive to toluene alleviates PC71BM solubility problems, reduces phase domain size by two orders of magnitude, and boosts efficiency from ηP = 0.02% to 6.10%. Both AFM and TEM imaging show that the Me-naph additive promotes a more finely phase-separated morphology in spin-coated films, while photoluminescence quenching and photoinduced absorption spectroscopy confirm that this finer morphology results in both better exciton quenching and more efficient charge separation.Organic Electronics 12/2012; 13(12):2870–2878. DOI:10.1016/j.orgel.2012.08.026 · 3.83 Impact Factor
Solar Cells - New Aspects and Solutions, 11/2011; , ISBN: 978-953-307-761-1
- "The addition of CN led to much finer phase separation between polymer and fullerene to form a fiber-like inter-penetrating morphology at the length scale of 20 nm, which is close to the ideal domain size, assuming an exciton diffusion length of 5- 10 nm (Markov et al., 2005; Scully et al., 2006; Shaw et al., 2008). By alternating bithiophene donating unit and DPP accepting unit, Janssen (Johan et al., 2009) developed P30, with an E g of 1.3eV. Terthiophene induced additional planarity, which enhanced packing and charge carrier mobility, as P30-based transistors exhibited nearly balanced hole and electron mobilities of 0.04 and 0.01cm 2 V -1 s -1 , respectively. "