Perylene diimides (PDIs) are attractive alternatives to fullerenes as electron transporters because of their optoelectronic properties, durability, and ease synthesis. Belying this promise, devices that utilize PDIs acceptors have low efficiencies. The primary deficiency in such cells is the short circuit current density (JSC), which traceable crystallinity PDIs. Therefore, disrupting without adversely impacting charge-transfer properties proposed an important design principle. This has been...

The origin of high current density in efficient non-fullerene based bulk heterojunction (BHJ) organic solar cells employing a non-planar perylene dimer (TP) as an electron acceptor and thiophene donor polymer PBDTTT-CT is investigated using electrical optical techniques. Photoluminescence measurements reveal almost complete quenching both the excitons, indicating hole transfer processes. nanomorphology films shows fine mixing TP at 50 : 50% weight ratio with photon to conversion efficiency...

The use of a diblock copolymer and novel dissymmetric perylene leads to improvement in the efficiency poly(3-hexylthiophene):perylene diimide solar cells. In films with copolymer, transmission electron micrographs indicate formation smaller domain sizes, photoluminescence component is partially quenched.

ADVERTISEMENT RETURN TO ISSUEPREVLetterNEXTDesign of Hydrogen Bond Catalysts Based on a Modular Oxazoline Template: Application to an Enantioselective Hetero Diels−Alder ReactionSridhar Rajaram and Matthew S. SigmanView Author Information Department Chemistry, University Utah, 315 South 1400 East, Salt Lake City, Utah 84112 Cite this: Org. Lett. 2005, 7, 24, 5473–5475Publication Date (Web):November 4, 2005Publication History Received22 September 2005Published online4 November inissue 1...

Dendronized diblock copolymers are prepared via ring opening metathesis polymerization. Atomic force microscopy imaging of individual molecules clearly establishes the presence structurally distinct blocks.

Substituted oxazoline amines have been prepared in high yield from beta-amino alcohols and Fmoc-protected alpha-amino acids using CCl(4), PPh(3), Hünig's base a one-pot procedure followed by base-mediated deprotection. [reaction: see text]

We report a comparison of charge carrier dynamics and device performance for low band gap polymer PBDTTT-CT in blends with the fullerene acceptor PC71BM PDI derivative similar electron affinities. Charge separation recombination are found to be remarkably these two acceptors, both exhibiting efficient, ultrafast (time constants 1.6 1.4 ps, respectively). The lower (1.75% compared 3.5% equivalent device) is shown result from slower transport, increasing nongeminate losses during collection.

We demonstrate the role of zinc oxide (ZnO) morphology and addition an acceptor interlayer to achieve high efficiency fullerene-free bulk heterojunction inverted organic solar cells. Nanopatterning ZnO buffer layer enhances effective light absorption in active layer, insertion a twisted perylene planarizes decreases electron extraction barrier. Along with increase current homogeneity, reduced work function difference selective transport electrons prevent accumulation charges decrease...

Abstract Herein, a meta‐analysis of the device performance and transient spectroscopic results are undertaken for various donor:acceptor blends, employing three different donor polymers seven acceptors including nonfullerene (NFAs). From this analysis, it is found that primary determinant external quantum efficiency (EQE) energy offset driving interfacial charge separation, Δ E CS . For devices polymer PffBT4T blended with NFA fullerene acceptors, an = 0.30 eV required to achieve near unity...

Ferroelectric films of poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) provide a controlled environment to study the aggregation tendency functional molecules such as perylene diimides (PDIs). The local electric field and free volume confinement parameters offered by matrix are tailored organizational assembly characteritics molecular acceptors. optical properties planar nonplanar PDIs in ferroelectric polymer were studied systematically over wide range that encompassed transition...

Benzyl aryl carbonates can react with a nucleophile to yield an activated electrophile and aryloxide anion. Previously, we had utilized this in the synthesis of α-nitro esters from nitroalkanes. To further understand process activation these by nucleophiles, have performed kinetic studies on hydrolysis using nucleophiles. Rate constants for were obtained under pseudo-first-order conditions DABCO as nucleophile. A comparison rate constant isobutyl phenyl carbonate benzyl shows that presence...

A blend of 10 vol % poly(methyl methacrylate) (PMMA) in a polystyrene (PS) matrix was prepared by mixing the polymers form 1.0 μm diameter latex particles, followed melt pressing powder at 110 °C into void-free films. These were annealed for various periods time 180 °C, and aggregation coalescence PMMA microspheres laser confocal fluorescence microscopy. Contrast provided fluorescent dye attached to polymer. Brownian motion as contributor could be ruled out. The major factor leading particle...

The monoanions of nitroalkanes are ambident nucleophiles that react with carbonate electrophiles through the oxygen atom. Products arising from reactivity at carbon atom will yield α-nitro esters, which precursors for α-amino esters. We demonstrate this in reactions benzyl phenyl and DABCO where esters obtained instead nitrile oxides. products readily reduced to This pathway could be a safe alternative Strecker reaction.

Abstract Aliphatic polycarbonates have been explored as environmentally benign alternatives to aromatic polycarbonates. Improvements the glass transition temperature ( T g ) of aliphatic pursued by several groups. We recently showed that attaching a pendant group poly(TMC) can enhance . Also, we shown para substituents on an impact Here, role bulky groups and effect substituent position ring. prepared novel naphthalene‐derived poly(TMC)s well 2‐Br‐substituted poly(PhTMC). The 2‐bromophenyl...

Abstract A Charge‐transfer (CT) states in bulk heterojunction (BHJ) solar cells play a decisive role determining the characteristics and performance of devices. The photophysical processes CT are closely investigated perylene based BHJ fullerene‐based BHJ. Comparison band‐tail photocurrent, PL/EL morphology reveal molecular structure‐property correlation on charge generation processes. inference drawn from these results points to decreased early recombination losses at polymer‐perylene...

Surface-Enhanced Raman Spectroscopy (SERS) is well-established as a tool for bio-diagnostics but often limited by analyte sensitivity and the need specialized substrates. Signal enhancement can be achieved attaching multiple markers to single analyte. Dendronic frameworks with attached periphery offer an opportunity examine this idea. In article, dendrons thiophenol groups on their were synthesized tested SERS For study, simple gold nanoparticles (∼60 nm) used substrate. A 102 fold in...